Chem Unit Four Video 3

okay we finished all children effort and children effect is effective kind of Shield so if we have electrons which are far from nucleus these electrons feel Shield of all other electrons which are on all um cells before the electron of Interest so the further is electron the more shielding effect I think that this is pretty intuitive this is clear and also I want you to understand that shielding effect is about four electrons so when we have um completed complete itself complete shell like no noble gas this is one shoot second completed shell also second shoe also Shield will be like completed 3D for example if we have 3D 10 those are also in inside our shielding effect uh so what is important can you see that shouldn't effort increases down their group but when we incite period children effect will be the same why it's so because for example for Lee soon please Zoom be released see that they are in this yellow the same shell number two for them core electrons will be hilu the same core electrons so all valence valence electrons of all these yellow guys will experience just one shooting effect just one shoe just one layer okay let us do some uh yes so we just let us do some activity here write abbreviated electron configurations okay let us do this first four hydrogen it will be helium helium uh two s two two B five and for chlorine chlorine is here we have Neon Neon 2s2 I'm sorry three is two three B5 so I see that uh valence electrons and let me Circle my valence electrons those thread are valence electrons of fluorine and those are valence electrons of a chlorine so helium is just one shell one layer and neon two layers two layers so because um I have more layers for chlorine I can say that children effect which experience valence of electrons of chlorine will be higher because two two two layers then a shielding effect that experience valence electrons of human Okay so away lens electron of chlorine and those are three s two and three B five experience more children because like two shells then valence electrons of fluorine here will be just one layer okay now let us compare fluorine and nitrogen fluorine is helium 2s 2 2B 5 in nitrogen helium two s two two B three it's here one two three I see that they both have um the same core electrons so the same core electrons the same children effect same or elect tools means the same children okay let us come and probably let us do like this sulfur and selenium silicon and phosphorus please do buy yourself I Do by myself we compare results okay all you need to know that if we have the same core electrons the same children effect different core electrons more layers more shielding air keeping this in mind sold this foreign okay let us compare results okay so uh sulfur has electron configuration Neon 3s23p4 three is two three before valence electrons selenium has argon 4s2 3G 10. 4p 4 let me check my valence will be 4s2 4p4 and Argon and also for 3D 10 will be my core electrons which give me these children because argon means more layers than neon I can say that valence electrons off selenium experience more children and in case of silicon enforcers the same children because neon neon the same Coral trust okay let us move to the next piece of information effect responsible for Effective nuclear charge let me explain what effective nuclear charges uh we know that each and hydrogen one proton and number of protons it will be charge of nucleus Z charge of nucleus so Church of chromium nucleus nucleus will be 24. positive but uh you know what because of shielding effect so let us say that charge Let Me Show an example here is Lee soon I believe and lisum has three three three protons so it's charge Z will be will be three but you know what because we have electrons which are further from my nucleus and I have some shielding some repulsion between them effective charge which feel my each electron is less so for example you see that this electron because of presence of other electrons will not like three it feel it feels like 260 69 only and electron which is on level number two because of this Sheldon effect feel not three but it feels less it feels 128 it's like in the example I gave you I believe I gave you that we have mama who has love plus three but baby which is close can fill this plastering but other children five-year-old feels like not Siri but let us say 1 25 and 15 years old can feel like zero seven because of shielding effect of other kids because of shielding effect of other electrons further electrons fear less effective charge what we need to know about effective charge look at at this um diagram these green shows us normal charge so you see that hydrogen has one proton helium two protons lithium-3 that is why I have nice uh straight line but actually what happened this blue represents effective nuclear charge and I see some something some um something first of all that this is smaller and I see some irregularities what is this first of all can you see that if I look at Elements which are in the same period like please so you see that they are in the same period effective nuclear charge increases nicely so I also can show can show it in in in this table so for lithium effective nuclear charge for wavelength valence electrons 128 for beryllium 129 and so don't can you see that it increases yes it's not three how it should be it's 128 yes it's not 4 like it should be for B really is one 91 but it increases it increases so I can say that across a period the valence um effective effective nuclear charge increases for valence electrons because it's increase in atomic number now let us look at um Elements which are in the same in the same group when we have elements in the same group effective nuclear charge also increases so let us look at this hydrogen has one at least soon 128 251 3.5 499 so yes for rubidium charge effective effective charge not effective just normal charge should be 37 outermost electrons feel like 4.99 but tendency is that effective nuclear charge increases how we can absorb this here okay look at this I'll look at hilu neon and argon so can you see that it increases but we have some irregularities and they are from hilum which is complete shell and uh listen which is next in periodic table but it will be on the next Shelf so here uh my effective nuclear charge decreases so let us read this across the period my effective nuclear charge increases down the group effective nuclear charge increases but from one period to another effective nuclear charge decreases and why it happened the appearance of additional shell so when you see that can you see that from for example hilum we start new shell the appearance of new additional shell overweight the increase in atomic number so we have just just in in here we have like kind of not the same as we have in Normal effect normal charge okay let us do some activity example number 15 to absorb this idea better indicate which atom in the following couple has higher nuclear Church Z and higher effective nuclear charge so nuclear charge I want you to memorize this it's just number of protons nothing else we can find it at periodic table easily effective nuclear charge we should find it in some tables for example I and I gave actually steps but let us compare okay fluorine and nitrogen fluorine has a nine protons I can find this information in periodic table and nitrogen has seven okay so I see that they have how many shells they are they are in Shell number two so shell number two so they are in the same shell they are in the same period which one has higher Z fluorine nine is higher than seven because D is just number of protons Z is number of products so fluorine let me write okay and which one Higher effective nuclear charge also fluoride when we have two atoms in the same period effective nuclear charge and nuclear charge have the same tendency okay next um fluorine and chlorine these two elements are in the same group so fluorine has nine and uh chlorine has 17. I can find it from periodic table 17 protons so higher affect your nuclear charge has chlorine because it has a it has a 17. protons okay number of shells fluorine has two shells and my chlorine has three shells so three shells but still higher effective nuclear charge will have chlorine because when we have atoms in the same group they also tendency is the same if we have higher nuclear charge we have higher effective super charge and one more example we have argon and potassium Argon has three shell as 18 okay 18 protons three shells and potassium has one more proton 19. but it has already four shells and and shells is unfavorable Factor okay so higher and higher charge higher number of protons will have Pata assume higher effective nuclear charge will have r so it will be only when I jump from three two four from two two three you see from from two to three from three to four so here is our example okay let us move to the next piece of information atomic radius atomic radius is the same as atomic we can think that it's the same as atomic size pretty much definition is defined as half the distance between the nuclei of neighboring atoms so for example if we have atom number one and number two this will be our atomic radius actually if you look at this because you see that this is half and this is half this is our diameter of one of pan atom so this is atomic radius um atomic radius or atomic size depends on two factors it depends or nuclear charge and number of shells now I want to give you some information nuclear church or number of protons can be visualized as magnet so just imagine we have nucleus and in nucleus we have protons and dislike magnet which tract electrons which are outside so just think about this in each nucleus in each atom inside nucleus we have magnet and magnet can be strong if we have a lot of products in magnet can be weak if we have not a lot of a lot of products um okay so before I continue I want you by the way to show side by side two diagrams first diagram is effective nuclear charge and second size of atom so can you see that actually what happened size of atom increases but we have some kind of jumps when we um look at this if I if I analyze my atoms in in one period so you see effective nuclear charge increases but can you see what happens with size it decreases then I see that um as my down down the group my size increases and it should be like this and I have these jumps so for example if I I see that uh Argan potassium effective nuclear charge of potassium is less than a size kind of opposite so it looks like size and effective nuclear charge they are kind of opposite if I have big effective nuclear charge I have small atom and this is true now I explain you why now this information this piece of information not intuitive that is why I ask I I ask your imagination to help you to memorize it look at this I told you in a second second before that Church in nucleus number of protons can be sold as magnet so look at this when I have listened I have just three protons inside so I try to show it's very small magnet so this blue what is here is nucleus and because it has three protons it's very very small magnet on the other hand when I have fluorine and Lee zoom and fluorine are in the same in the same period fluorine has a nine protons inside so it's like very strong magnet that is why I showed this blue is look less or fluorine and this magnet I try to I try to in I tried to you to to visualize this so what happened very weak Magnet or listen uh two electrons but not very strongly that is why lithium is Big ETA my flooring pull outside electrons strongly like suck them because it's drunk magnet and it make my fluorine shrink flooring is small I know it's it's controversial because it is intuitive if I look at this I can say that probably next atom will be bigger no it is not fluorine is small and and listen is big and all because fluorine has strong magnet which outside electrons you might ask me because I kept this question also but I see that here I have a lot of electrons and here I have just three electrons but you know what magnet have its own relationship with each one electron so um a number of electrons doesn't matter what what what matter is how strong magnet or how weak magnet so more protons higher charge and higher charge means higher effective nuclear charge if I am in my period the smaller atom this I ask you to memorize it okay let us read this because it will be like um summary across a period the atomic size decrease is the effective nuclear charge increases uh when shell stays the same outer electrons are pulled closer to the nucleus the thus the atom are smaller okay next down the group down the group is pretty easy intuitive so no problems with that in down the Grooms at group atomic radius or atomic size increase why because number of shell shells increase so we see that hydrogen has just one shell so hydrogen is small and cesium has a seven shells that is why oh six shells that is why cesium is big pretty intuitive and we have this jump from one period to another so you see that um size decrease so if we compare let us say if you compare helium and lisu hilum and listen listen is in period um in Period one that is why listen will be bigger than hilu okay let us do some activity referring to a periodic table arrange the following atoms in order of increasing atomic radius okay first I have phosphorus Arsenic and nitrogen if I look at periodic table I see that all these guys are in the same in in the same group they are here and I nitrogen phosphorus are silly okay nitrogen phosphorus are same I see that my nitrogen has two shells phosphorus three shells arsenic has four shells that is why my nitrogen will be small my arsenic will be big I for now I compare just these three does it make sense it's pretty easy and they ask us a range in order of increasing let us do this nitrogen is smaller than phosphorus phosphorus is smaller than arsenic smallest biggest okay let us move to A to B uh now I have silicone uh sodium aluminum magnesium if I look at periodic table I see that my silicone aluminum sodium magnesium are in the same period And I will write them as as they appear a periodic table so soju agnesium then I have aluminum and then I have a silicone if I have guys from the same period I need to compare their magnets number of products that is it okay so number of protons sodium has 11 and silicon 14 literature 14 years 14. braddons means strongest magnet I'll write it down and strongest magnet pull outside electrons and my silicon shrinks Throne magnet makes Autumn or any species smaller so which one is smallest smallest okay which is biggest from these four sodium perfect and they ask us to arrange in order of increasing okay so silicon is smaller than aluminum aluminum is smaller than magnesium magnesium is smaller than soju okay silicone smallest small egg and we have one more uh so we have potassium Argan and calcium let me uh calcium potassium okay I see that I have a Pata soon and calcium and they will be in group one two three four in Period number four and I see that my argon in Period number three if I have problem like this I need to compare them first I probably work with two guys which are in the same period and remember that when I have guys from the same period I need to compare number of protons I need to compare uh magnets when I tell you Madness it's not very scientific I just want your imagination help you has 19 okay which magnet is stronger calcium or potassium calcium okay so uh Stronger magnet run magnet smaller so I can tell you that uh calcium calcium will be smaller than potassium potassium will be bigger calcium will be small but now my argon has just three shells and these guys have four shells so my argon will be even smaller smallest the smallest so I have Argon smaller than calcium and calcium is smaller than potassium so this is smallest this is biggest okay um let us move to the next piece of information we talk about Atomic radios now we are going to talk about ionic radius before we continue I just want to show you data that big picture look at this um I created for you this so you see we have Radia we have size of atoms by the way can you see that really soon biggest and flooring is smooth so for me if you if you use a little bit imagination you see that it looks like triangle listen is big and fluorine is small and also a listen is small and cesium is Big so here we have one more triangle but now look at Atomic ionic Raji Raji so what is here let us compare item and iron atom of listen and uh cation of listen which one is smaller Italian or atom cation is smaller so I see that lithium plus is smaller okay now compare nitrogen neutral atom and nitrite and ion what is bigger anion anion is bigger can you see nitrogen is small atom small and iron is B but um but what can I see is it my triangles I still have triangles here the SE triangle for cations this is triangle for anions I also will have triangle like this not nice no not pretty Okay so cations are smaller than their parent atoms why it's so we take electrons off and atom gets smaller so we like take away some matter from our atom so here is picture so you see for example beryllium a parent which is big and cattayam is small second piece of information and anions are negative are bigger than their parent atoms why it's so we add additional electrodes we kind of add matter that is why my electron become bigger so here is a illustration we have oxygen for example and oxide anion is bigger than parent now what are um what are our thread ayani karaji decrease across the period so you see that I told you that uh atomic radius ready decree decrease fluorine is smoothly so much big but ions if if I if I look at cations so we see Lee soon is big and carbon 4 plus is small so they decrease across the period and it also through four anions they decrease across the period because nitrogen nitrite is bigger and F minus is smaller here I have just one kind of Arrow and when I have I ions I should have like two errors because I can talk I should talk separately about separately about Italians and separately about anions um and but what happened down the group ionic Raji increase down the group why it's so because more shall this is intuitive you see that listen has just two shells sodium three shells and so do one um let me also try to explain what happened here why why our lisum is smaller than Lee soon parent look at periodic table what happened with Lee soon to become Lee soon Plus here I need to get rid of one electron and I will be as good as hilum so it looks like Lee soon plus has just one shell that is why Lee soon plus is smaller and uh look at my for example I don't know Carbon or I'm sorry not carbon nitrogen when it's get it gets more electrons it will be bigger so technically our Lee soon Plus is all our cations they they have like downgrade they move to lower shell that is why they're small cations are small and now it's Arby okay let us move considers the following species I give you species carbon carbon for plus carbon mine four minus by the way sometimes you will see this in might see this in textbooks they can give you in um they can ask you to compare pretty different and pretty crazy pretty weird particles okay I I can guarantee that something like this do not exist at normal conditions but for sure scientists can create some strange conditions to produce some crazy stuff and for sure we can compare size of this crazy stuff who cares yeah so okay we have Karma we have carbon four plus and we have carbon core minus you know what let us compare it's always good idea to compare number of protons and number of electrons how many protons have all these three species all of them you have the same products six because number of protons it's like ID of element and my element can become or can become um a time or a nine number of protons will be the same so six protons six and six number of electrons for atom of carbon six are number of electrons for such a particle carbon four plus two and here will be 10. so uh which one will be the biggest [Music] this is biggest which one is smallest this is smallest this will be in the middle okay which is most so let us write down like this C4 La plus four plus okay four plus smaller than carbon and smaller the carbon 4 minus small big okay let us move to the next consider period three ions which is the smallest which is the biggest cation and any time we compare ions from the same period it's we need to compare number of patterns and electrons because radons means magnet okay sodium sodium 11 is 11 protons magnesium 12 protons aluminum 13 patterns you see 13 12. okay now could you please help me and tell how many electrons sodium plus has ten yes absolutely correct so look at this if I want to create sodium plus I need to to lose one electron and then I will be as good as neon and neon has 10 electrons what can be said about magnesium and uh two plus an aluminum Surplus how many electrons 10. nice which is smallest which one has strongest magnet aluminum yes so if you see 13 biggest number let us even write it down throw on this magnet so this is smallest because my magnet with strengths so chill these poor 10 electrons and my aluminum Surplus shrinks it's tiny it's small uh and which one is the biggest sodium okay now let us compare first phosphite sulfite chloride phosphorus has 15 6 16 17 Brothers and could you please deduce how many electrons phosphide will have 18 because 15 plus 1 plus 2 plus 3 plus 3 more electrons it will have 18 electrons so my my uh phosphide phosphide is as good as organ so 8 18 and what about sulfite and chloride how many electrons in 1818 again biggest magnet strongest magnet I see that this guy is strongest magnet throne guest magnet foreign so which is smallest particle chloride I just look at this number and which is biggest mm-hmm that is it so I ask you you should have like strong algorithm in your head no intuition switch it off because intuition doesn't work here it's counter counter intuition just strongest magnet bigger number bigger number of product and smaller particles okay um good let us yeah no I see some tour this term tells me Isa electronic ions actually isoelectronic ions and atoms have the same number of electrons so they have the same configuration actually you know what in chemistry and I guess in science Isa means the same I the electronic means the same number of electrons and look at this can you see that my sodium plus magnesium to plus and aluminum Surplus are Isa electronic and the same can be set about three particles B3 minus S2 minus and C L minus r i the electronic because they have the same number of electrons okay now consider the following ions and atom are the following ions is electronic okay let us work with them we have species I will write them like they gave me as Neon sodium plus mg two plus aluminum three plus or no no first nitrogen nitrogen three minus nitrite oxygen to minus oxide and chlorine F minus fluoride okay uh electron electron configuration could you please tell me yeah probably with neon it will it goes it's clear that electron configuration of neon can be written as neon in in this bracket but what about sodium plus what is electron configuration of sodium Plus foreign Plus Neon so aluminum Surplus what is uh configuration electronic configuration aluminum three plus three p what one okay aluminum three plus what is configuration of aluminum Surplus Neon what about O2 minus what is electron configuration of o2 minus you know what all of them all these guys have electron configuration neon period okay so number of uh electrons number of electrons neon has how many 10. 10 10 10 10 10 now number of patterns my neon has 10 protons sodium has 11 magnesium has 12 aluminum has 13 nitrogen has seven oxygen has eight and fluorine has nine okay those guys are isoelectronic that is why I can compare them I know that some of them cation some of them are nice they are in different periods but if they are isoelectronic so if they are isilotronic yes so for my a isilotronic yes if they are is electronic I can compare this their size using idea of strongest magnet okay which particle has strongest magnet more products most protons strongest magnet so which particle is the smallest I told you strongest magnet smallest particle yes so this guy is smallest okay which is weakest magnet here nitrogen so weakest so this guy will be biggest guy that is why I told you you can't counter intuitive take your intuition and put it out switch it off just through otherwise okay so they won't ask arrange the conspicious in order of increasing yeah okay in for the increasing nuclear charge increase in nuclear charge increase in nuclear charge so my smallest nuclear charge is nitrogen uh my second second is a nitrogen 3 plus oxygen to minus then we have F minus what is my next seven eight nine after that I have what yeah after that I have sodium plus then I have magnesium two plus and then I have aluminum three plus so what I did I answered question B arrange each of the following species in order of increasing nuclear charge and now see they ask me arrange each of the following ions in order of decreasing alphionic radius I see that I just figured out that my nitrite is Biggest Part decreasing biggest particle so I start from biggest so I have n three plus biggest what is my second biggest O2 minus then I have F minus that I have neon then I have sodium plus then I have magnesium two plus then I have aluminum three plus and this guy is smallest but yes it is true if you look um here so can you see that your I don't know if you have uh aluminum and can you see night right nitrite is bigger I know it's so that is why just rules just business nothing personal tell them to tell to them so you have guessed rules okay let us move to the next give uh after after the part okay let us let us complete one in 21 and up and then we have small rest give some cations anions and atom which are either electronic with BR minus I ask you please do it by yourself do by myself tan okay let us check it's extremely important for you to try so I think first I figure out that electron configuration of my bromine minus brahmite my bromite anion is nothing else but Krypton so I need to find any species which have the same configuration so if I am talking about cations those my candidates so if I rubidium will be loser of one electron so I have rubidium plus it will be as good as crypto if I have strong shoe two plus if my strontium will lose loses two electrons I will have again Krypton so my rubidium and strontium rubidium plus instruction to Plus answer Score first one second one anion and iron is negative uh okay bromine is here selenium is actually my only choice if I have selenium and add to it two more electrons I will receive Krypton and atom atoms should be noble gas which Noble guess Krypton itself okay does it make sense thank you a question like this for sure will be an exam you know what I want you to pay attention sometimes by the way it's very often I ask students give me get tired which is either electronic with bromine and students give me answer this is correct answer in some sense it's eyes electronic but it is not cation is positive cats are good and onion is bad negative when we cry onion we when we cut onion we cry so it's bad negative okay and one more example arrange each of the following pairs of ions in order of increasing atomic radius okay so magnesium and calcium when I look at these two guys I see that they are in the same in the same group calcium and magnesium sorry okay but I see that my magnesium has three layers three shells and calcium four shells which is biggest which is biggest yes absolutely yeah so magnesium is small calcium is big but the same magnesium two plus is small and calcium to plus is Big just because one have more layers Okay so two three four layers so a magnesium we want in order of increasing magnesium two plus smaller than calcium two plus small big okay next uh when we have guys which are in the same period we want to compare protons and neutrons always okay our phosphorus has 15 phosphorus has 15 and chlorine has a 17. 15 17 and number of electrons okay could you please help me how many electrons 18. okay which one has strongest magnet let me write and strongest magnet electron close to itself and make our CL minus small so this guy is small this guy is big if we compare two of them so we want um like arrange increasing so I will write down CL minus is smaller than b three minus one more case we have copper plus and copper two plus if we will talk about our products 2929 49 protons 29 products number of electrons how many electrons do I have in Copper Plus 28 and here 27. okay let's matter smaller particle in this case I have less electrons and number of magnet is the same but less less matter so this guy will be small this guy will be big so uh copper II plus is smaller than copper plus small big one more question here and this question is which pair or pairs are is oelectronic okay could you please answer this question a magnesium two plus and calcium to plus are they Isa electronic no because if if you want if you want to compare magnesium to plus has 10 electrons and calcium to Plus has 18 electrons uh what about case b are they either electronic yes because they have the same number of electrons so these guys eyes what about Case C are these two guys coppers Isaac electronic no because you see 8 and 27. no okay let us let's have small rest next piece of information is about ionization energy ah first definition energy is energy in kilojoules because all energy can be measured in kilojoules is energy required for complete removal of one mole of electrons from one mole of gazillus atoms or ions okay so let us try to understand this definition let us say we have atom atom is shown here so and atom is our system Adam has some nucleus with protons and this green are electrons outside and uh Atomic system and I am surroundings so I need to apply energy to Steel electron through my atom atom is not happy about this he has its own electron and I am going to steal that is why I make some work on atom that is why Delta h of my system is positive because surroundings that surrounded does some work okay and Delta H is positive so I have a I have endosormic process in the solving process and uh after that what I have I have cation and electron so here is how our equation looks like atom gives us X Plus and some electron is stolen by surroundings and it is in the thermic process uh what can be said here is a small periodic table and it gives us information that ionization energy G increases across a period so if I take like like these guys let us say please boron carbon nitrogen oxygen fluorine neon there in the same period anization energy increases so please soon has low ionization energy and neon has high ionization energy why it's so because of effective nuclear charge because of a nuclear charge just think about this do you remember that our neon has strong magnet just try to steal electron to remove electron from restaurant from a strong magnet is difficult that is why my neon will have higher ionization energy than liso okay let us read this immunization energy increases across the period the large nuclear charge result it's more difficult to remove the electron okay but what about down the group down the group down the group immunization energy decreases why the outermost electrons is further away from the nucleus and feels less at attraction so look at this hydrogen has its electron very close but for example franchume it has one two three four five six seven these electrons is far away yes we might have even strong magnet but it's so far aways that I can tow it pretty easily remove it pretty easily not like with a hydrogen so if you see in this periodic table I showed you that helium has highest possible ionization energy highest possible annulation energy and francium has lowest possible ionization energy okay uh also um yeah by the way what this means high ionization energy and low organization energy I know I change it a little bit maybe in your lecture notes you have slightly different I change it just before our lecture so okay High organization energy what does it mean it is difficult to take electron out so it's high ionization energy I get I have greedy atom my my mind not touchy I'm not going to give you my electron so that is why it's high elevation Edge and low organization energy means it is easy to take electron out from atom this mean that I have e low ionization energy okay now what we have here is some diagram and this diagram means what do I have here ionization energy e ionization i e is stands for ionization energy versus atomic number what can I say can you see that if I if I uh look at my period so you see it's period one ionization energy generally increases you can absorb it but we have some uh some irregularities and these irregularities group three a and group 6A more precisely it will be and nitrogen I see that they are kind of higher than they than they should be so you see that if my burial is decent guy and will be the place it should be and nitrogen will be decent guy so then my my line will be much smoother I see that my nitrogen and beryllium kind of jump why it's so to understand it let us solve our let us show let us solve example number 22. plain some irregularities in the first ionization energy across a period by the way for the first time I can see something first ionization energy this means that it's possible to have second ionization energy sword and whatever we we will discover about ionization energy second and third in couple minutes now let us um analyze this first organization energy okay listen and by the way ionization energies are given 520 899 and so don't 520 means I need to apply 520 kilojoules to remove one mole of electrons from one mole of atoms okay electron configuration is um one is two two is one for beryllium I dry I I write just um valence electrons two is two for Boron two is two two b one for carbon two s two two B two for nitrogen two s two two B three oxygen two s two two e four n for fluorine two is two two P five nice now uh my uh diagrams for listening just this one for Berry Loom these two four Boron three four carbon one two one two four nitrogen one two one two three four oxygen one two one two three and for fluorine it will be one two one two one okay nice this information about our atom but what happened if I create when I remove one electrode electron configuration of listen will be just hilum which is the same as one as two it will be hilum two s one and it will be just one orbital in case of listen plus I will have amp empty 2 s sub level okay a poor Boron it will be 2s 2 and that is it because you see what what happened I I just removed I just remove one electron yep so here I have one two nice for carbon this will be removed so I have two s two two b one for nitrogen this one will be removed so I have two s two two P two and for oxygen this one will be probably this one will be removed actually it doesn't matter but for sure okay it should be so 2s 2 2 B 3 2 1 two three and four my last one this one will be removed so we have two s two two B four look at this I see that irregularities are for boron and for oxygen I didn't expect but it it is a it is uh less than it should be ah okay I told you that these guys jump up actually uh what is really happened my these guys jump down mind um why it happened for Boron look at this we had we had um 2s2 2b1 and after after I removed one electron I have 2s2 so I have half I have uh completely healed 2s sub-level is energetically favorable yeah you've ever seen this good here energetically favorable so it looks like it's much easier it's much easier to remove electron forward and this is true because I go from less favorable state to more favorable state and that is why boron has less than expected it should be a little bit higher but but it it is lower okay and now look at oxygen so you see that it oxygen comes from uh 2s2 2B 4 2 2s2 2p3 in this case I have half field 2p sub level and it also energetically favorable and that is why for oxygen we have a ionization energy lower than it expected we expect it it should be higher okay yeah let me okay okay let us move to the next piece of information if we have many electron atoms they can lose more than one electron that is why actually we can have first ionization energy second ionization energy when we remove second electron sort and immunization energy and so do on uh by the way can you see that first ionization energy is always smaller than second ionization energy and second ionization energy is always smaller than certainization energy why it's so that's amazing situation uh this is person and this person has three hundred dollars three bills 100 100 imagine situation I removed I stole 100 from this person is not happy but he or she didn't expect so it was pretty easy for me then I want to remove second one hundred dollars now it's harder my person is alert and she fights but if I try to stall sort three hundred dollars my person will fight like lion so that is why certainization energy when I when I remove sword electron is much higher than previous one make sense yeah so here in this table um you can see successive ionization energy for some elements so you see for listen uh first initiation Energy number of when I wanted to remove just one electron is 520 second ionization energy and third ionization energy so you you see but probably you notice that some numbers are shown red I explained in second why so first first of all let us read this because it's like summary for the same element the successive ionization energy is higher than the previous one for example the second generation energy energies higher than fuel sterilization energy and now the the successive ionization energy is much higher than previous one if if the electron is removed from the closed shell so what happened here if I need to break noble gas configuration then my person fight like 100 lines that is why this ionization energy will be really high let me show example because we need to understand this uh consider six successive organization energies for carbon explained the huge increase of ionization energy five okay my carbon has a configuration 2 is 2 2 beam how many two so I have we want two configuration okay one is two two is two two P two one two three four five six if I remove just one electron I remove I have one two three four five okay then I remove one more electron I have so I release this one one two three four that is it then I remove one more electrode so I have one two three and then I remove one more electron and I have one two that is it and then I remove one more electron and I have just just one and also I can remove even one more minus electron and I have nothing but look at these numbers let us analyze them one thousand two thousand four thousand sixty six thousand and then thirty seven thousand just think about this 6 000 approximately and 37 even 38 000. I have huge jump between removing second removing electron number number four and electron number five why it's so so can you see that when I am here this is a electron configuration of helium Noble gas configuration stable and then if I remove one more electron I break stable Noble guess configuration and this is unfavorable process my carbon hates a that is why I have to fight like Lion to steal this electron so in this case um Noble guess configuration is broken okay let us move to the next example um which one of the following atoms should have larger first ionization energy if I look at cesium in bedroom I see that they are in the same period And I know that down the period down there previewed ionization energies increases but okay let us move to this first one okay but let us analyze season is no so it's like Xenon and then I have one two three four five six six S one but you know what they also I see they want uh to feel this 5p and you see my 5p is here is 5p because one two three four here is five b five b so I have a configuration is Xenon 6s1 but I want to fill all of them so we see I want you to understand that these guys belong to Xenon and for barium I will have configuration Xenon 6s 2. okay if I remove one electron if I remove an electron this one and this one I have um here a configuration of xenon and here configuration of Xenon 6s1 so you see that it's very easy to remove electron configuration it's very easy to remove um electron for seism here because I will come to very stable stable uh state that is why my prediction is that ionization energy first off will be lower that ionization energy first of value I'll just leave you immunization energy it should be it should highest it should has highest sure it will be available yeah okay nice now let us move to the next I just wanted to check next I remove second electron second electron my uh in this case what I have I have not Xenon anymore I have Krypton Krypton and after Krypton I have five five s two four D ten four D ten and I have five b five because I removed one electron this process is very unfavorable favor so I expect that this ionization should be huge and in my uh in in case of barium when I remove this electron I will receive nice table configuration of of xenon stable so I expect that this will be small because it it is not very difficult to uh to remove electron from pain or blast so my expectation is that ionization energy 2 of cesium will be bigger that ionization energy two of barium okay this is first case let us move to yeah yeah let us move to the next one you see that my uh say zoom and bear you they will be they were in the same period now let us talk about nitrogen and phosphorus they are in in the same group so configuration of nitrogen nitrogen is here will be hilum hilum 2s2 2p3 one two one two three and phosphorus is neon 3s2 3p 3 let me check two one two three just because they are in the same group their successive con um ionization energy will have the same pattern so okay if I remove just one electron this and something like this if I remove one more oh so my expectation is it's much easier to to remove electron from level three then from level two so ionization energy first of phosphorus will be smaller than ionization energy first of nitrogen in the same with second second immunization energy of phosphorus will be smaller that second ionization energy of nitrogen because it's easier to remove electron from level which is further from the nucleus okay let us move to the next test week sense those in my opinion those examples are this analysis is difficult but you you might have questions like this to an example that is why you need to understand how to analyze so this is about electron ionization energy no essential energy is about stealing of electron now electron affinity first definition then I explain it in simple words electron affinity is energy released when one mole of electron is added to one mole of atoms so look at this I have my system is atom I am surroundings and I give electron is present to my system What forms when I give electron anion is force my atom is so happy that I gave present happiness happiness is energy out this process is exothermic because my system release energy kind of happiness because I gave I am surrounding gave a present to it um here is how electron affinity increase decrease electron affinity increases across a period so fluorine will have higher electron affinity than lisume happiness of fluorine happiness about present is much higher that happiness listen about my presence why it's so the larger nuclear charge result it is easier to hold additional electron so if I give additional electron to fluorine fluorine is happy because it can hold with its big magnet additional electron lisu it's difficult to hold their own its own electrons and I gave him present ah happiness so so what about down there period across the period my in my electron affinity is decreases so francium has very low happiness about receiving additional electron why so a lot of layers it's difficult for friendship to take care to hold its own electrons and I gave it one more happiness pretty much low listen listen will be happier than fracture but about electron affinity we we have one more very important detail noble gases have very low electron affinities all these cases have negative happiness why it's so just think about this my helium is ideal it has electron configuration of completed electron configuration because it's noble gas and now my gift electron if I give additional electron to helium I break its own stability ideal stability so taking electron or helium and any other noble gas it's very unfavorable process negative happiness okay so if we look here is here is a diagram which shows electron affinity I know that it looks like kind of but still we can see some rules electron affinity increases from left to right in Period so look at this if I look at Helium to okay listen listen listen from ah what happened from from Lee soon from Lee soon to fluorine my electron affinity increases generally I also see some irregularities and in this case my irregularities be re-loom and nitrogen they kind of low they can kind of have less happiness when I give additional electrons my dear friends let us go through I know it's like you do you feel tired but you know what the good things no problems okay we will have some problems we had I hope you had a chance to watch episode number one and we had some problems there but that is it no calculation but a lot of Concepts after this unit I will ask you what is better problems in stoichiometry or concepts concept Concepts here okay let's see so listen again electron configuration uh I have a two as one two is two two s two two B uh one two s two two B two two s two two B three two s two two B four and two s two two P five my lines my my arrow arrows my electrons okay so what happened I gave additional additional electron to all these species so electron configuration will be two s two two s two two P one two s two two B two two two B three two s two two B four two s two two P five and two is two two b six so which will be one two one two three one two three four one two one two one two and here is complete electron shell very nice okay uh my irregularity is here and there I want to know why my beryllium is not so heavy weight happiness is pretty low look at this I had 2s2 field Qs orbital field 2s subshell with sub shop and I moved to less favorable less stable higher energy 2s2 2p1 so from more favorable State I came to less favorable state that is why happiness of my beryllium is pretty low it might be higher but it is not and the same I can be said about nitrogen it had a 2s3 half field half field half field I'm sorry not three s two two two piece three two P three half field B sub show favorable and I moved to situation which is 2s2 2p 4 Less favorable that is why happiness of my nitrogen is also pretty low so let us move to the next question why noble gases have low electron affinity energy why why noble gases has low happiness if I give it additional electron because stability will be lost because if I give additional electron to noble gas stable favorable noble gas electron configuration will be broken if Noble guess [Music] stable configuration will be broken so B is it likely that neon will form anion neon minus it's likely no very unlikely you know what ah let us do 28 29 and and then we have small rest Which element would have largest electron affinity you know what uh because a lot of new terms I want you to translate in your mind what is electron affinity electron affinity is happiness about receiving additional electron so um in Azeroth who desires electronic okay we have a lithium sodium potassium Revenue first I look at periodic table I just want to figure out where they are okay I see that my guys are here in in in in in this group number one so I have listened rubidium and I also see that my Lee sung has two layers uh sodium has three layers potassium four layers rubidium should have I guess five two three four five yes and imagine situation I give additional electron to each one which one has highest happiness in which one is lowest happiness listen has what happens the most cabinets yeah so this guy has highest electron affinity largest largest electron affinity and this guy has lowest electron affinity okay this was ma this was a lb I have sodium sulfur chlorine and Argon I want to so sodium sodium sodium sodium sulfur sodium sulfur chlorine in art as I see that these guys in the same period so sodium sulfur chlorine and Argon okay taking in consideration that I have noble gas which one which one out of this four has lowest heaviness argon okay these guys has lowest lowest electron affinity and now uh let us consider these three so we have sodium sulfur and chlorine which one has from these three now I just look at this three which one has lowest this one then goes which from the three which one has highest which one has lowest which one has highest chlorine and this this will be the lowest from these three so if I want to figure out which one has lowest lowest I I have something like this Argon then I have sodium then I have sulfur then I have chlorine this has lowest this is highest electron affinity electron affinity okay and one more if you look at electron affinity which I gave you probably you notice some strange can you see I showed you that lowest electron affinity is fraction by the way lowest ionization energy also was fraction but highest ionization highest electron affinity not noble gases but it's okay it is chlorine chlorine has highest it's higher than chlorine so actually our next problem is about this fluorine has lower than chlorine electronic Affinity electron affinity despite the fact that it has smaller atomic size so it can smaller atomic side this means it can hold electrons more effectively and here are and why it's why fluorine is an anomaly so we we also have numbers so we see chlorine has highest 394 and fluorine is lower 328. also you can see this in this chart can you see chlorine is highest and fluorine should be somewhere higher but no it is lower any ideas Maybe if I tell you about size is what is bigger fluorine or chlorine chlorine has two layers chlorine has three layers what what is bigger chlorine is bigger okay so here is our fluorine here is our Glory and all of them they have seven valence electrons valence electrons how do I know it's seven group seven eight step 7A so let us show the sentence one two three four five six seven ah I write like this okay and chlorine also seven one two three four five six seven in case of smooth fluorine we have huge repulsion between valence electrodes now imagine situation I add one more electron repulsion in case of fluorine will be even bigger than huge and this repulsion will make happiness about receiving present smaller so repulsion of electrons in small fluorine makes ionization energy of fluorine smaller than ionization oh I'm sorry electron affinity electron affinity because of repulsion repulsion is so big that it's kind of make electron affinity School one very very small piece of information went last um sometimes students cannot understand what is the difference between organization energy and electronicity first of all in ionization energy I steal electron from somebody and uh electron affinity I still I still Electronics yeah ionization energy I still electron and absorb how my how my atom fights if it fights a lot exhibition energy is big if it fights her not so strong I know that ionization energy is low and electron affinity about present I give you 100 and your happiness is electron affinity if you love this my present your happiness so high if not electron affinity school so actually I love my electrons it's about high ionization energy if I have hyonization energy I love my electrons and I will fight you are not going to steal it if I have high electron affinity I want your electron badly so because okay let us do small rest we're going to talk about is metallic Behavior so you know what I know that we know that um we have a non-metals here and metals here and those are metalloids but actually you know what if we look at periodic table our properties will change step by step so it's not like border metals non-metals our purposes change step by step so metallic character or metallic Behavior will change will will change like it's shown in in this small periodic table so here helium will have uh hilum has non-metallic Behavior and fluorine let us say chlorine and francium has the best metallic Behavior metal behavior is connected with low ionization energy so that is why metals are easy loose electrons and form cations okay one is one let me I illustrate this in in this reaction when iron and iron is metal reacts with oxygen product will be rust iron 2 or 3. it is by the way balance this reaction okay if it's oh if it's an odd make it even I see odd make it even for three well done but look at this our iron was Zero oxidation number of iron was zero and our iron in compound in my rust is plus three so I see that my iron is loser of three electrons loser reducer oxidized and we know that and we know that reducer is the same as reducing agent okay so when metal react with non-metal to form ionic compound metal acts as reducing agent agent reducing agent also to show you how yeah you you don't have this I just add this I actually I always do this but I write it down now I have it so you just need to rewrite I also also want to show how properties change how properties metals and non-metals change in in an example of oxides so can you see that sodium oxide magnesium oxide aluminum oxide sulfur oxide so all these oxides are compounds is our elements with oxygens and I if you look at sodium Magnum magnesium magnesium and aluminum so you see that all these guys in one period but I can tell you that sodium is metal and uh chlorine is non-metal non-metal so we have like transition in metals form basic oxides basic and non-metals form acidic and you will see how it changed from metal basic and non-metal acidic okay when my basic oxide reacts with water it gives me sodium hydroxide which is deal it as a balance so okay one one two two one two okay we're good we're both magnesium hydroxide reacts with water also also gave me magnesium hydroxide which is base okay let us balance it okay it's it it is balanced already okay one two okay good I'll so this is also basic my aluminum hydroxide aluminum 203 is amphoteric um amphoteric means not acidic not basic both see dick and basic aluminum 203 is can be said main component of clay and you know that Clay is not soluble in water but aluminum oxide can react with acids and base and in this we can see that aluminum hydroxide has acidic and basic properties okay if it reacts with acid it will form aluminum cl3 plus water let us balance two aluminums two aluminums and um six will be six and I should have three Waters if my aluminum reacts with base so this is a bay this is acid base it will form complex compound it is a sodium aluminum o h four types so still we have some reaction okay let us balance um two aluminums I put two here now I have two sodiums I put two here now let us count uh hydrogens uh how many hydrogens do I have here four multiplied by two eight hydrogens two hydrogens here I need six hydrogen okay balanced my so you see that this guy is amphoteric silicon oxide is sand for sure you know that sand will not react with water scent is not soluble in water and this guy is slightly acidic silicon oxide do not react with acid but it will react with a base and it form sodium silicon or stream and what what is our and water so let us balance it sodium to surgery okay so we have two one two three yeah done get balanced Bells and now my uh phosphorus oxide with water will give me phosphoric acid a h3po4 let us balance four phosphorus I will put four here and and four multiplied by three twelve so I need to put a 6 here so four multiply before 16 Oxygen 16 oxygens balanced so you see that this is acidic because it produce acid then my SO3 also acidic it it gives me h2so4 yes it's balanced already here I have per chloric acid h c l o four two let us see if it's balanced yes it's balanced so I want you to show this let us go through this so can you see that we start with something extremely basic because it it forms base and we finish with something very acidic which gives us very strong acid and a sodium to chlorine they are in the same period so you see that properties change in periodic table okay and one last example of how properties change periodically boiling point of neon boiling point so BP is boiling point by the way um MP it's melting point if you see somewhere okay boiling point of neon is negative 245.9 degrees Celsius a boiling point of Krypton is negative 150 2.9 degrees Celsius we want to know we want to estimate what is boiling point of argon I noticed that I neon encryption they are here in periodic table neon encryption and argon is in B because I know that all properties change step by step I can deduce that argon will have boiling point average let us estimate it so boiling point of argon will be negative 245.9 Plus negative 152.9 degrees Celsius and divide by 2. delete so a negative 2 or 240 5.9 minus 152.9 here my number is 3 negative 3 98.8 and divided by two so uh my boiling point estimated of argon is negative 199.4 degrees Celsius sure it's it's not exact number but it should be pretty pretty close prediction just because I know that all properties will change periodically and step by step and one more piece of information because you you might have this an exam we learn that we have alkaline Earth's Metals in group 1A we learn that we have oh ah 1A alkali metals 1A alkaline alkali 2A alkaline Earths metals eight a noble gases halogens we know transition metals I want you to know one more categories of elements those are rare earth metals and they are candium youth room and lutacion and Lam lanzanites if you look at this periodic table these guys and these guys so because in in exam you might be asked is let us say samarium rare rare burst metal and you need to say yes that is it ah the funny moment is that they are not rare actually scientists very often make mistakes because you see they thought that those elements are rare but after a while they found that a lot of these elements these metals so but I want you to know this category okay we are done with lecture

okay we finished all children effort and children effect is effective kind of Shield so if we have electrons which are far from nucleus these electrons feel Shield of all other electrons which are on all um cells before the electron of Interest so the further is electron the more shielding effect I think that this is pretty intuitive this is clear and also I want you to understand that shielding effect is about four electrons so when we have um completed complete itself complete shell like no noble gas this is one shoot second completed shell also second shoe also Shield will be like completed 3D for example if we have 3D 10 those are also in inside our shielding effect uh so what is important can you see that shouldn't effort increases down their group but when we incite period children effect will be the same why it's so because for example for Lee soon please Zoom be released see that they are in this yellow the same shell number two for them core electrons will be hilu the same core electrons so all valence valence electrons of all these yellow guys will experience just one shooting effect just one shoe just one layer okay let us do some uh yes so we just let us do some activity here write abbreviated electron configurations okay let us do this first four hydrogen it will be helium helium uh two s two two B five and for chlorine chlorine is here we have Neon Neon 2s2 I'm sorry three is two three B5 so I see that uh valence electrons and let me Circle my valence electrons those thread are valence electrons of fluorine and those are valence electrons of a chlorine so helium is just one shell one layer and neon two layers two layers so because um I have more layers for chlorine I can say that children effect which experience valence of electrons of chlorine will be higher because two two two layers then a shielding effect that experience valence electrons of human Okay so away lens electron of chlorine and those are three s two and three B five experience more children because like two shells then valence electrons of fluorine here will be just one layer okay now let us compare fluorine and nitrogen fluorine is helium 2s 2 2B 5 in nitrogen helium two s two two B three it's here one two three I see that they both have um the same core electrons so the same core electrons the same children effect same or elect tools means the same children okay let us come and probably let us do like this sulfur and selenium silicon and phosphorus please do buy yourself I Do by myself we compare results okay all you need to know that if we have the same core electrons the same children effect different core electrons more layers more shielding air keeping this in mind sold this foreign okay let us compare results okay so uh sulfur has electron configuration Neon 3s23p4 three is two three before valence electrons selenium has argon 4s2 3G 10. 4p 4 let me check my valence will be 4s2 4p4 and Argon and also for 3D 10 will be my core electrons which give me these children because argon means more layers than neon I can say that valence electrons off selenium experience more children and in case of silicon enforcers the same children because neon neon the same Coral trust okay let us move to the next piece of information effect responsible for Effective nuclear charge let me explain what effective nuclear charges uh we know that each and hydrogen one proton and number of protons it will be charge of nucleus Z charge of nucleus so Church of chromium nucleus nucleus will be 24. positive but uh you know what because of shielding effect so let us say that charge Let Me Show an example here is Lee soon I believe and lisum has three three three protons so it's charge Z will be will be three but you know what because we have electrons which are further from my nucleus and I have some shielding some repulsion between them effective charge which feel my each electron is less so for example you see that this electron because of presence of other electrons will not like three it feel it feels like 260 69 only and electron which is on level number two because of this Sheldon effect feel not three but it feels less it feels 128 it's like in the example I gave you I believe I gave you that we have mama who has love plus three but baby which is close can fill this plastering but other children five-year-old feels like not Siri but let us say 1 25 and 15 years old can feel like zero seven because of shielding effect of other kids because of shielding effect of other electrons further electrons fear less effective charge what we need to know about effective charge look at at this um diagram these green shows us normal charge so you see that hydrogen has one proton helium two protons lithium-3 that is why I have nice uh straight line but actually what happened this blue represents effective nuclear charge and I see some something some um something first of all that this is smaller and I see some irregularities what is this first of all can you see that if I look at Elements which are in the same period like please so you see that they are in the same period effective nuclear charge increases nicely so I also can show can show it in in in this table so for lithium effective nuclear charge for wavelength valence electrons 128 for beryllium 129 and so don't can you see that it increases yes it's not three how it should be it's 128 yes it's not 4 like it should be for B really is one 91 but it increases it increases so I can say that across a period the valence um effective effective nuclear charge increases for valence electrons because it's increase in atomic number now let us look at um Elements which are in the same in the same group when we have elements in the same group effective nuclear charge also increases so let us look at this hydrogen has one at least soon 128 251 3.5 499 so yes for rubidium charge effective effective charge not effective just normal charge should be 37 outermost electrons feel like 4.99 but tendency is that effective nuclear charge increases how we can absorb this here okay look at this I'll look at hilu neon and argon so can you see that it increases but we have some irregularities and they are from hilum which is complete shell and uh listen which is next in periodic table but it will be on the next Shelf so here uh my effective nuclear charge decreases so let us read this across the period my effective nuclear charge increases down the group effective nuclear charge increases but from one period to another effective nuclear charge decreases and why it happened the appearance of additional shell so when you see that can you see that from for example hilum we start new shell the appearance of new additional shell overweight the increase in atomic number so we have just just in in here we have like kind of not the same as we have in Normal effect normal charge okay let us do some activity example number 15 to absorb this idea better indicate which atom in the following couple has higher nuclear Church Z and higher effective nuclear charge so nuclear charge I want you to memorize this it's just number of protons nothing else we can find it at periodic table easily effective nuclear charge we should find it in some tables for example I and I gave actually steps but let us compare okay fluorine and nitrogen fluorine has a nine protons I can find this information in periodic table and nitrogen has seven okay so I see that they have how many shells they are they are in Shell number two so shell number two so they are in the same shell they are in the same period which one has higher Z fluorine nine is higher than seven because D is just number of protons Z is number of products so fluorine let me write okay and which one Higher effective nuclear charge also fluoride when we have two atoms in the same period effective nuclear charge and nuclear charge have the same tendency okay next um fluorine and chlorine these two elements are in the same group so fluorine has nine and uh chlorine has 17. I can find it from periodic table 17 protons so higher affect your nuclear charge has chlorine because it has a it has a 17. protons okay number of shells fluorine has two shells and my chlorine has three shells so three shells but still higher effective nuclear charge will have chlorine because when we have atoms in the same group they also tendency is the same if we have higher nuclear charge we have higher effective super charge and one more example we have argon and potassium Argon has three shell as 18 okay 18 protons three shells and potassium has one more proton 19. but it has already four shells and and shells is unfavorable Factor okay so higher and higher charge higher number of protons will have Pata assume higher effective nuclear charge will have r so it will be only when I jump from three two four from two two three you see from from two to three from three to four so here is our example okay let us move to the next piece of information atomic radius atomic radius is the same as atomic we can think that it's the same as atomic size pretty much definition is defined as half the distance between the nuclei of neighboring atoms so for example if we have atom number one and number two this will be our atomic radius actually if you look at this because you see that this is half and this is half this is our diameter of one of pan atom so this is atomic radius um atomic radius or atomic size depends on two factors it depends or nuclear charge and number of shells now I want to give you some information nuclear church or number of protons can be visualized as magnet so just imagine we have nucleus and in nucleus we have protons and dislike magnet which tract electrons which are outside so just think about this in each nucleus in each atom inside nucleus we have magnet and magnet can be strong if we have a lot of products in magnet can be weak if we have not a lot of a lot of products um okay so before I continue I want you by the way to show side by side two diagrams first diagram is effective nuclear charge and second size of atom so can you see that actually what happened size of atom increases but we have some kind of jumps when we um look at this if I if I analyze my atoms in in one period so you see effective nuclear charge increases but can you see what happens with size it decreases then I see that um as my down down the group my size increases and it should be like this and I have these jumps so for example if I I see that uh Argan potassium effective nuclear charge of potassium is less than a size kind of opposite so it looks like size and effective nuclear charge they are kind of opposite if I have big effective nuclear charge I have small atom and this is true now I explain you why now this information this piece of information not intuitive that is why I ask I I ask your imagination to help you to memorize it look at this I told you in a second second before that Church in nucleus number of protons can be sold as magnet so look at this when I have listened I have just three protons inside so I try to show it's very small magnet so this blue what is here is nucleus and because it has three protons it's very very small magnet on the other hand when I have fluorine and Lee zoom and fluorine are in the same in the same period fluorine has a nine protons inside so it's like very strong magnet that is why I showed this blue is look less or fluorine and this magnet I try to I try to in I tried to you to to visualize this so what happened very weak Magnet or listen uh two electrons but not very strongly that is why lithium is Big ETA my flooring pull outside electrons strongly like suck them because it's drunk magnet and it make my fluorine shrink flooring is small I know it's it's controversial because it is intuitive if I look at this I can say that probably next atom will be bigger no it is not fluorine is small and and listen is big and all because fluorine has strong magnet which outside electrons you might ask me because I kept this question also but I see that here I have a lot of electrons and here I have just three electrons but you know what magnet have its own relationship with each one electron so um a number of electrons doesn't matter what what what matter is how strong magnet or how weak magnet so more protons higher charge and higher charge means higher effective nuclear charge if I am in my period the smaller atom this I ask you to memorize it okay let us read this because it will be like um summary across a period the atomic size decrease is the effective nuclear charge increases uh when shell stays the same outer electrons are pulled closer to the nucleus the thus the atom are smaller okay next down the group down the group is pretty easy intuitive so no problems with that in down the Grooms at group atomic radius or atomic size increase why because number of shell shells increase so we see that hydrogen has just one shell so hydrogen is small and cesium has a seven shells that is why oh six shells that is why cesium is big pretty intuitive and we have this jump from one period to another so you see that um size decrease so if we compare let us say if you compare helium and lisu hilum and listen listen is in period um in Period one that is why listen will be bigger than hilu okay let us do some activity referring to a periodic table arrange the following atoms in order of increasing atomic radius okay first I have phosphorus Arsenic and nitrogen if I look at periodic table I see that all these guys are in the same in in the same group they are here and I nitrogen phosphorus are silly okay nitrogen phosphorus are same I see that my nitrogen has two shells phosphorus three shells arsenic has four shells that is why my nitrogen will be small my arsenic will be big I for now I compare just these three does it make sense it's pretty easy and they ask us a range in order of increasing let us do this nitrogen is smaller than phosphorus phosphorus is smaller than arsenic smallest biggest okay let us move to A to B uh now I have silicone uh sodium aluminum magnesium if I look at periodic table I see that my silicone aluminum sodium magnesium are in the same period And I will write them as as they appear a periodic table so soju agnesium then I have aluminum and then I have a silicone if I have guys from the same period I need to compare their magnets number of products that is it okay so number of protons sodium has 11 and silicon 14 literature 14 years 14. braddons means strongest magnet I'll write it down and strongest magnet pull outside electrons and my silicon shrinks Throne magnet makes Autumn or any species smaller so which one is smallest smallest okay which is biggest from these four sodium perfect and they ask us to arrange in order of increasing okay so silicon is smaller than aluminum aluminum is smaller than magnesium magnesium is smaller than soju okay silicone smallest small egg and we have one more uh so we have potassium Argan and calcium let me uh calcium potassium okay I see that I have a Pata soon and calcium and they will be in group one two three four in Period number four and I see that my argon in Period number three if I have problem like this I need to compare them first I probably work with two guys which are in the same period and remember that when I have guys from the same period I need to compare number of protons I need to compare uh magnets when I tell you Madness it's not very scientific I just want your imagination help you has 19 okay which magnet is stronger calcium or potassium calcium okay so uh Stronger magnet run magnet smaller so I can tell you that uh calcium calcium will be smaller than potassium potassium will be bigger calcium will be small but now my argon has just three shells and these guys have four shells so my argon will be even smaller smallest the smallest so I have Argon smaller than calcium and calcium is smaller than potassium so this is smallest this is biggest okay um let us move to the next piece of information we talk about Atomic radios now we are going to talk about ionic radius before we continue I just want to show you data that big picture look at this um I created for you this so you see we have Radia we have size of atoms by the way can you see that really soon biggest and flooring is smooth so for me if you if you use a little bit imagination you see that it looks like triangle listen is big and fluorine is small and also a listen is small and cesium is Big so here we have one more triangle but now look at Atomic ionic Raji Raji so what is here let us compare item and iron atom of listen and uh cation of listen which one is smaller Italian or atom cation is smaller so I see that lithium plus is smaller okay now compare nitrogen neutral atom and nitrite and ion what is bigger anion anion is bigger can you see nitrogen is small atom small and iron is B but um but what can I see is it my triangles I still have triangles here the SE triangle for cations this is triangle for anions I also will have triangle like this not nice no not pretty Okay so cations are smaller than their parent atoms why it's so we take electrons off and atom gets smaller so we like take away some matter from our atom so here is picture so you see for example beryllium a parent which is big and cattayam is small second piece of information and anions are negative are bigger than their parent atoms why it's so we add additional electrodes we kind of add matter that is why my electron become bigger so here is a illustration we have oxygen for example and oxide anion is bigger than parent now what are um what are our thread ayani karaji decrease across the period so you see that I told you that uh atomic radius ready decree decrease fluorine is smoothly so much big but ions if if I if I look at cations so we see Lee soon is big and carbon 4 plus is small so they decrease across the period and it also through four anions they decrease across the period because nitrogen nitrite is bigger and F minus is smaller here I have just one kind of Arrow and when I have I ions I should have like two errors because I can talk I should talk separately about separately about Italians and separately about anions um and but what happened down the group ionic Raji increase down the group why it's so because more shall this is intuitive you see that listen has just two shells sodium three shells and so do one um let me also try to explain what happened here why why our lisum is smaller than Lee soon parent look at periodic table what happened with Lee soon to become Lee soon Plus here I need to get rid of one electron and I will be as good as hilum so it looks like Lee soon plus has just one shell that is why Lee soon plus is smaller and uh look at my for example I don't know Carbon or I'm sorry not carbon nitrogen when it's get it gets more electrons it will be bigger so technically our Lee soon Plus is all our cations they they have like downgrade they move to lower shell that is why they're small cations are small and now it's Arby okay let us move considers the following species I give you species carbon carbon for plus carbon mine four minus by the way sometimes you will see this in might see this in textbooks they can give you in um they can ask you to compare pretty different and pretty crazy pretty weird particles okay I I can guarantee that something like this do not exist at normal conditions but for sure scientists can create some strange conditions to produce some crazy stuff and for sure we can compare size of this crazy stuff who cares yeah so okay we have Karma we have carbon four plus and we have carbon core minus you know what let us compare it's always good idea to compare number of protons and number of electrons how many protons have all these three species all of them you have the same products six because number of protons it's like ID of element and my element can become or can become um a time or a nine number of protons will be the same so six protons six and six number of electrons for atom of carbon six are number of electrons for such a particle carbon four plus two and here will be 10. so uh which one will be the biggest [Music] this is biggest which one is smallest this is smallest this will be in the middle okay which is most so let us write down like this C4 La plus four plus okay four plus smaller than carbon and smaller the carbon 4 minus small big okay let us move to the next consider period three ions which is the smallest which is the biggest cation and any time we compare ions from the same period it's we need to compare number of patterns and electrons because radons means magnet okay sodium sodium 11 is 11 protons magnesium 12 protons aluminum 13 patterns you see 13 12. okay now could you please help me and tell how many electrons sodium plus has ten yes absolutely correct so look at this if I want to create sodium plus I need to to lose one electron and then I will be as good as neon and neon has 10 electrons what can be said about magnesium and uh two plus an aluminum Surplus how many electrons 10. nice which is smallest which one has strongest magnet aluminum yes so if you see 13 biggest number let us even write it down throw on this magnet so this is smallest because my magnet with strengths so chill these poor 10 electrons and my aluminum Surplus shrinks it's tiny it's small uh and which one is the biggest sodium okay now let us compare first phosphite sulfite chloride phosphorus has 15 6 16 17 Brothers and could you please deduce how many electrons phosphide will have 18 because 15 plus 1 plus 2 plus 3 plus 3 more electrons it will have 18 electrons so my my uh phosphide phosphide is as good as organ so 8 18 and what about sulfite and chloride how many electrons in 1818 again biggest magnet strongest magnet I see that this guy is strongest magnet throne guest magnet foreign so which is smallest particle chloride I just look at this number and which is biggest mm-hmm that is it so I ask you you should have like strong algorithm in your head no intuition switch it off because intuition doesn't work here it's counter counter intuition just strongest magnet bigger number bigger number of product and smaller particles okay um good let us yeah no I see some tour this term tells me Isa electronic ions actually isoelectronic ions and atoms have the same number of electrons so they have the same configuration actually you know what in chemistry and I guess in science Isa means the same I the electronic means the same number of electrons and look at this can you see that my sodium plus magnesium to plus and aluminum Surplus are Isa electronic and the same can be set about three particles B3 minus S2 minus and C L minus r i the electronic because they have the same number of electrons okay now consider the following ions and atom are the following ions is electronic okay let us work with them we have species I will write them like they gave me as Neon sodium plus mg two plus aluminum three plus or no no first nitrogen nitrogen three minus nitrite oxygen to minus oxide and chlorine F minus fluoride okay uh electron electron configuration could you please tell me yeah probably with neon it will it goes it's clear that electron configuration of neon can be written as neon in in this bracket but what about sodium plus what is electron configuration of sodium Plus foreign Plus Neon so aluminum Surplus what is uh configuration electronic configuration aluminum three plus three p what one okay aluminum three plus what is configuration of aluminum Surplus Neon what about O2 minus what is electron configuration of o2 minus you know what all of them all these guys have electron configuration neon period okay so number of uh electrons number of electrons neon has how many 10. 10 10 10 10 10 now number of patterns my neon has 10 protons sodium has 11 magnesium has 12 aluminum has 13 nitrogen has seven oxygen has eight and fluorine has nine okay those guys are isoelectronic that is why I can compare them I know that some of them cation some of them are nice they are in different periods but if they are isoelectronic so if they are isilotronic yes so for my a isilotronic yes if they are is electronic I can compare this their size using idea of strongest magnet okay which particle has strongest magnet more products most protons strongest magnet so which particle is the smallest I told you strongest magnet smallest particle yes so this guy is smallest okay which is weakest magnet here nitrogen so weakest so this guy will be biggest guy that is why I told you you can't counter intuitive take your intuition and put it out switch it off just through otherwise okay so they won't ask arrange the conspicious in order of increasing yeah okay in for the increasing nuclear charge increase in nuclear charge increase in nuclear charge so my smallest nuclear charge is nitrogen uh my second second is a nitrogen 3 plus oxygen to minus then we have F minus what is my next seven eight nine after that I have what yeah after that I have sodium plus then I have magnesium two plus and then I have aluminum three plus so what I did I answered question B arrange each of the following species in order of increasing nuclear charge and now see they ask me arrange each of the following ions in order of decreasing alphionic radius I see that I just figured out that my nitrite is Biggest Part decreasing biggest particle so I start from biggest so I have n three plus biggest what is my second biggest O2 minus then I have F minus that I have neon then I have sodium plus then I have magnesium two plus then I have aluminum three plus and this guy is smallest but yes it is true if you look um here so can you see that your I don't know if you have uh aluminum and can you see night right nitrite is bigger I know it's so that is why just rules just business nothing personal tell them to tell to them so you have guessed rules okay let us move to the next give uh after after the part okay let us let us complete one in 21 and up and then we have small rest give some cations anions and atom which are either electronic with BR minus I ask you please do it by yourself do by myself tan okay let us check it's extremely important for you to try so I think first I figure out that electron configuration of my bromine minus brahmite my bromite anion is nothing else but Krypton so I need to find any species which have the same configuration so if I am talking about cations those my candidates so if I rubidium will be loser of one electron so I have rubidium plus it will be as good as crypto if I have strong shoe two plus if my strontium will lose loses two electrons I will have again Krypton so my rubidium and strontium rubidium plus instruction to Plus answer Score first one second one anion and iron is negative uh okay bromine is here selenium is actually my only choice if I have selenium and add to it two more electrons I will receive Krypton and atom atoms should be noble gas which Noble guess Krypton itself okay does it make sense thank you a question like this for sure will be an exam you know what I want you to pay attention sometimes by the way it's very often I ask students give me get tired which is either electronic with bromine and students give me answer this is correct answer in some sense it's eyes electronic but it is not cation is positive cats are good and onion is bad negative when we cry onion we when we cut onion we cry so it's bad negative okay and one more example arrange each of the following pairs of ions in order of increasing atomic radius okay so magnesium and calcium when I look at these two guys I see that they are in the same in the same group calcium and magnesium sorry okay but I see that my magnesium has three layers three shells and calcium four shells which is biggest which is biggest yes absolutely yeah so magnesium is small calcium is big but the same magnesium two plus is small and calcium to plus is Big just because one have more layers Okay so two three four layers so a magnesium we want in order of increasing magnesium two plus smaller than calcium two plus small big okay next uh when we have guys which are in the same period we want to compare protons and neutrons always okay our phosphorus has 15 phosphorus has 15 and chlorine has a 17. 15 17 and number of electrons okay could you please help me how many electrons 18. okay which one has strongest magnet let me write and strongest magnet  electron close to itself and make our CL minus small so this guy is small this guy is big if we compare two of them so we want um like arrange increasing so I will write down CL minus is smaller than b three minus one more case we have copper plus and copper two plus if we will talk about our products 2929 49 protons 29 products number of electrons how many electrons do I have in Copper Plus 28 and here 27. okay let's matter smaller particle in this case I have less electrons and number of magnet is the same but less less matter so this guy will be small this guy will be big so uh copper II plus is smaller than copper plus small big one more question here and this question is which pair or pairs are is oelectronic okay could you please answer this question a magnesium two plus and calcium to plus are they Isa electronic no because if if you want if you want to compare magnesium to plus has 10 electrons and calcium to Plus has 18 electrons uh what about case b are they either electronic yes because they have the same number of electrons so these guys eyes what about Case C are these two guys coppers Isaac electronic no because you see 8 and 27. no okay let us let's have small rest next piece of information is about ionization energy ah first definition energy is energy in kilojoules because all energy can be measured in kilojoules is energy required for complete removal of one mole of electrons from one mole of gazillus atoms or ions okay so let us try to understand this definition let us say we have atom atom is shown here so and atom is our system Adam has some nucleus with protons and this green are electrons outside and uh Atomic system and I am surroundings so I need to apply energy to Steel electron through my atom atom is not happy about this he has its own electron and I am going to steal that is why I make some work on atom that is why Delta h of my system is positive because surroundings that surrounded does some work okay and Delta H is positive so I have a I have endosormic process in the solving process and uh after that what I have I have cation and electron so here is how our equation looks like atom gives us X Plus and some electron is stolen by surroundings and it is in the thermic process uh what can be said here is a small periodic table and it gives us information that ionization energy G increases across a period so if I take like like these guys let us say please boron carbon nitrogen oxygen fluorine neon there in the same period anization energy increases so please soon has low ionization energy and neon has high ionization energy why it's so because of effective nuclear charge because of a nuclear charge just think about this do you remember that our neon has strong magnet just try to steal electron to remove electron from restaurant from a strong magnet is difficult that is why my neon will have higher ionization energy than liso okay let us read this immunization energy increases across the period the large nuclear charge result it's more difficult to remove the electron okay but what about down the group down the group down the group immunization energy decreases why the outermost electrons is further away from the nucleus and feels less at attraction so look at this hydrogen has its electron very close but for example franchume it has one two three four five six seven these electrons is far away yes we might have even strong magnet but it's so far aways that I can tow it pretty easily remove it pretty easily not like with a hydrogen so if you see in this periodic table I showed you that helium has highest possible ionization energy highest possible annulation energy and francium has lowest possible ionization energy okay uh also um yeah by the way what this means high ionization energy and low organization energy I know I change it a little bit maybe in your lecture notes you have slightly different I change it just before our lecture so okay High organization energy what does it mean it is difficult to take electron out so it's high ionization energy I get I have greedy atom my my mind not touchy I'm not going to give you my electron so that is why it's high elevation Edge and low organization energy means it is easy to take electron out from atom this mean that I have e low ionization energy okay now what we have here is some diagram and this diagram means what do I have here ionization energy e ionization i e is stands for ionization energy versus atomic number what can I say can you see that if I if I uh look at my period so you see it's period one ionization energy generally increases you can absorb it but we have some uh some irregularities and these irregularities group three a and group 6A more precisely it will be and nitrogen I see that they are kind of higher than they than they should be so you see that if my burial is decent guy and will be the place it should be and nitrogen will be decent guy so then my my line will be much smoother I see that my nitrogen and beryllium kind of jump why it's so to understand it let us solve our let us show let us solve example number 22. plain some irregularities in the first ionization energy across a period by the way for the first time I can see something first ionization energy this means that it's possible to have second ionization energy sword and whatever we we will discover about ionization energy second and third in couple minutes now let us um analyze this first organization energy okay listen and by the way ionization energies are given 520 899 and so don't 520 means I need to apply 520 kilojoules to remove one mole of electrons from one mole of atoms okay electron configuration is um one is two two is one for beryllium I dry I I write just um valence electrons two is two for Boron two is two two b one for carbon two s two two B two for nitrogen two s two two B three oxygen two s two two e four n for fluorine two is two two P five nice now uh my uh diagrams for listening just this one for Berry Loom these two four Boron three four carbon one two one two four nitrogen one two one two three four oxygen one two one two three and for fluorine it will be one two one two one okay nice this information about our atom but what happened if I create when I remove one electrode electron configuration of listen will be just hilum which is the same as one as two it will be hilum two s one and it will be just one orbital in case of listen plus I will have amp empty 2 s sub level okay a poor Boron it will be 2s 2 and that is it because you see what what happened I I just removed I just remove one electron yep so here I have one two nice for carbon this will be removed so I have two s two two b one for nitrogen this one will be removed so I have two s two two P two and for oxygen this one will be probably this one will be removed actually it doesn't matter but for sure okay it should be so 2s 2 2 B 3 2 1 two three and four my last one this one will be removed so we have two s two two B four look at this I see that irregularities are for boron and for oxygen I didn't expect but it it is a it is uh less than it should be ah okay I told you that these guys jump up actually uh what is really happened my these guys jump down mind um why it happened for Boron look at this we had we had um 2s2 2b1 and after after I removed one electron I have 2s2 so I have half I have uh completely healed 2s sub-level is energetically favorable yeah you've ever seen this good here energetically favorable so it looks like it's much easier it's much easier to remove electron forward and this is true because I go from less favorable state to more favorable state and that is why boron has less than expected it should be a little bit higher but but it it is lower okay and now look at oxygen so you see that it oxygen comes from uh 2s2 2B 4 2 2s2 2p3 in this case I have half field 2p sub level and it also energetically favorable and that is why for oxygen we have a ionization energy lower than it expected we expect it it should be higher okay yeah let me okay okay let us move to the next piece of information if we have many electron atoms they can lose more than one electron that is why actually we can have first ionization energy second ionization energy when we remove second electron sort and immunization energy and so do on uh by the way can you see that first ionization energy is always smaller than second ionization energy and second ionization energy is always smaller than certainization energy why it's so that's amazing situation uh this is person and this person has three hundred dollars three bills 100 100 imagine situation I removed I stole 100 from this person is not happy but he or she didn't expect so it was pretty easy for me then I want to remove second one hundred dollars now it's harder my person is alert and she fights but if I try to stall sort three hundred dollars my person will fight like lion so that is why certainization energy when I when I remove sword electron is much higher than previous one make sense yeah so here in this table um you can see successive ionization energy for some elements so you see for listen uh first initiation Energy number of when I wanted to remove just one electron is 520 second ionization energy and third ionization energy so you you see but probably you notice that some numbers are shown red I explained in second why so first first of all let us read this because it's like summary for the same element the successive ionization energy is higher than the previous one for example the second generation energy energies higher than fuel sterilization energy and now the the successive ionization energy is much higher than previous one if if the electron is removed from the closed shell so what happened here if I need to break noble gas configuration then my person fight like 100 lines that is why this ionization energy will be really high let me show example because we need to understand this uh consider six successive organization energies for carbon explained the huge increase of ionization energy five okay my carbon has a configuration 2 is 2 2 beam how many two so I have we want two configuration okay one is two two is two two P two one two three four five six if I remove just one electron I remove I have one two three four five okay then I remove one more electron I have so I release this one one two three four that is it then I remove one more electrode so I have one two three and then I remove one more electron and I have one two that is it and then I remove one more electron and I have just just one and also I can remove even one more minus electron and I have nothing but look at these numbers let us analyze them one thousand two thousand four thousand sixty six thousand and then thirty seven thousand just think about this 6 000 approximately and 37 even 38 000. I have huge jump between removing second removing electron number number four and electron number five why it's so so can you see that when I am here this is a electron configuration of helium Noble gas configuration stable and then if I remove one more electron I break stable Noble guess configuration and this is unfavorable process my carbon hates a that is why I have to fight like Lion to steal this electron so in this case um Noble guess configuration is broken okay let us move to the next example um which one of the following atoms should have larger first ionization energy if I look at cesium in bedroom I see that they are in the same period And I know that down the period down there previewed ionization energies increases but okay let us move to this first one okay but let us analyze season is no so it's like Xenon and then I have one two three four five six six S one but you know what they also I see they want uh to feel this 5p and you see my 5p is here is 5p because one two three four here is five b five b so I have a configuration is Xenon 6s1 but I want to fill all of them so we see I want you to understand that these guys belong to Xenon and for barium I will have configuration Xenon 6s 2. okay if I remove one electron if I remove an electron this one and this one I have um here a configuration of xenon and here configuration of Xenon 6s1 so you see that it's very easy to remove electron configuration it's very easy to remove um electron for seism here because I will come to very stable stable uh state that is why my prediction is that ionization energy first off will be lower that ionization energy first of value I'll just leave you immunization energy it should be it should highest it should has highest sure it will be available yeah okay nice now let us move to the next I just wanted to check next I remove second electron second electron my uh in this case what I have I have not Xenon anymore I have Krypton Krypton and after Krypton I have five five s two four D ten four D ten and I have five b five because I removed one electron this process is very unfavorable favor so I expect that this ionization should be huge and in my uh in in case of barium when I remove this electron I will receive nice table configuration of of xenon stable so I expect that this will be small because it it is not very difficult to uh to remove electron from pain or blast so my expectation is that ionization energy 2 of cesium will be bigger that ionization energy two of barium okay this is first case let us move to yeah yeah let us move to the next one you see that my uh say zoom and bear you they will be they were in the same period now let us talk about nitrogen and phosphorus they are in in the same group so configuration of nitrogen nitrogen is here will be hilum hilum 2s2 2p3 one two one two three and phosphorus is neon 3s2 3p 3 let me check two one two three just because they are in the same group their successive con um ionization energy will have the same pattern so okay if I remove just one electron this and something like this if I remove one more oh so my expectation is it's much easier to to remove electron from level three then from level two so ionization energy first of phosphorus will be smaller than ionization energy first of nitrogen in the same with second second immunization energy of phosphorus will be smaller that second ionization energy of nitrogen because it's easier to remove electron from level which is further from the nucleus okay let us move to the next test week sense those in my opinion those examples are this analysis is difficult but you you might have questions like this to an example that is why you need to understand how to analyze so this is about electron ionization energy no essential energy is about stealing of electron now electron affinity first definition then I explain it in simple words electron affinity is energy released when one mole of electron is added to one mole of atoms so look at this I have my system is atom I am surroundings and I give electron is present to my system What forms when I give electron anion is force my atom is so happy that I gave present happiness happiness is energy out this process is exothermic because my system release energy kind of happiness because I gave I am surrounding gave a present to it um here is how electron affinity increase decrease electron affinity increases across a period so fluorine will have higher electron affinity than lisume happiness of fluorine happiness about present is much higher that happiness listen about my presence why it's so the larger nuclear charge result it is easier to hold additional electron so if I give additional electron to fluorine fluorine is happy because it can hold with its big magnet additional electron lisu it's difficult to hold their own its own electrons and I gave him present ah happiness so so what about down there period across the period my in my electron affinity is decreases so francium has very low happiness about receiving additional electron why so a lot of layers it's difficult for friendship to take care to hold its own electrons and I gave it one more happiness pretty much low listen listen will be happier than fracture but about electron affinity we we have one more very important detail noble gases have very low electron affinities all these cases have negative happiness why it's so just think about this my helium is ideal it has electron configuration of completed electron configuration because it's noble gas and now my gift electron if I give additional electron to helium I break its own stability ideal stability so taking electron or helium and any other noble gas it's very unfavorable process negative happiness okay so if we look here is here is a diagram which shows electron affinity I know that it looks like kind of but still we can see some rules electron affinity increases from left to right in Period so look at this if I look at Helium to okay listen listen listen from ah what happened from from Lee soon from Lee soon to fluorine my electron affinity increases generally I also see some irregularities and in this case my irregularities be re-loom and nitrogen they kind of low they can kind of have less happiness when I give additional electrons my dear friends let us go through I know it's like you do you feel tired but you know what the good things no problems okay we will have some problems we had I hope you had a chance to watch episode number one and we had some problems there but that is it no calculation but a lot of Concepts after this unit I will ask you what is better problems in stoichiometry or concepts concept Concepts here okay let's see so listen again electron configuration uh I have a two as one two is two two s two two B uh one two s two two B two two s two two B three two s two two B four and two s two two P five my lines my my arrow arrows my electrons okay so what happened I gave additional additional electron to all these species so electron configuration will be two s two two s two two P one two s two two B two two two B three two s two two B four two s two two P five and two is two two b six so which will be one two one two three one two three four one two one two one two and here is complete electron shell very nice okay uh my irregularity is here and there I want to know why my beryllium is not so heavy weight happiness is pretty low look at this I had 2s2 field Qs orbital field 2s subshell with sub shop and I moved to less favorable less stable higher energy 2s2 2p1 so from more favorable State I came to less favorable state that is why happiness of my beryllium is pretty low it might be higher but it is not and the same I can be said about nitrogen it had a 2s3 half field half field half field I'm sorry not three s two two two piece three two P three half field B sub show favorable and I moved to situation which is 2s2 2p 4 Less favorable that is why happiness of my nitrogen is also pretty low so let us move to the next question why noble gases have low electron affinity energy why why noble gases has low happiness if I give it additional electron because stability will be lost because if I give additional electron to noble gas stable favorable noble gas electron configuration will be broken if Noble guess [Music] stable configuration will be broken so B is it likely that neon will form anion neon minus it's likely no very unlikely you know what ah let us do 28 29 and and then we have small rest Which element would have largest electron affinity you know what uh because a lot of new terms I want you to translate in your mind what is electron affinity electron affinity is happiness about receiving additional electron so um in Azeroth who desires electronic okay we have a lithium sodium potassium Revenue first I look at periodic table I just want to figure out where they are okay I see that my guys are here in in in in in this group number one so I have listened rubidium and I also see that my Lee sung has two layers uh sodium has three layers potassium four layers rubidium should have I guess five two three four five yes and imagine situation I give additional electron to each one which one has highest happiness in which one is lowest happiness listen has what happens the most cabinets yeah so this guy has highest electron affinity largest largest electron affinity and this guy has lowest electron affinity okay this was ma this was a lb I have sodium sulfur chlorine and Argon I want to so sodium sodium sodium sodium sulfur sodium sulfur chlorine in art as I see that these guys in the same period so sodium sulfur chlorine and Argon okay taking in consideration that I have noble gas which one which one out of this four has lowest heaviness argon okay these guys has lowest lowest electron affinity and now uh let us consider these three so we have sodium sulfur and chlorine which one has from these three now I just look at this three which one has lowest this one then goes which from the three which one has highest which one has lowest which one has highest chlorine and this this will be the lowest from these three so if I want to figure out which one has lowest lowest I I have something like this Argon then I have sodium then I have sulfur then I have chlorine this has lowest this is highest electron affinity electron affinity okay and one more if you look at electron affinity which I gave you probably you notice some strange can you see I showed you that lowest electron affinity is fraction by the way lowest ionization energy also was fraction but highest ionization highest electron affinity not noble gases but it's okay it is chlorine chlorine has highest it's higher than chlorine so actually our next problem is about this fluorine has lower than chlorine electronic Affinity electron affinity despite the fact that it has smaller atomic size so it can smaller atomic side this means it can hold electrons more effectively and here are and why it's why fluorine is an anomaly so we we also have numbers so we see chlorine has highest 394 and fluorine is lower 328. also you can see this in this chart can you see chlorine is highest and fluorine should be somewhere higher but no it is lower any ideas Maybe if I tell you about size is what is bigger fluorine or chlorine chlorine has two layers chlorine has three layers what what is bigger chlorine is bigger okay so here is our fluorine here is our Glory and all of them they have seven valence electrons valence electrons how do I know it's seven group seven eight step 7A so let us show the sentence one two three four five six seven ah I write like this okay and chlorine also seven one two three four five six seven in case of smooth fluorine we have huge repulsion between valence electrodes now imagine situation I add one more electron repulsion in case of fluorine will be even bigger than huge and this repulsion will make happiness about receiving present smaller so repulsion of electrons in small fluorine makes ionization energy of fluorine smaller than ionization oh I'm sorry electron affinity electron affinity because of repulsion repulsion is so big that it's kind of make electron affinity School one very very small piece of information went last um sometimes students cannot understand what is the difference between organization energy and electronicity first of all in ionization energy I steal electron from somebody and uh electron affinity I still I still Electronics yeah ionization energy I still electron and absorb how my how my atom fights if it fights a lot exhibition energy is big if it fights her not so strong I know that ionization energy is low and electron affinity about present I give you 100 and your happiness is electron affinity if you love this my present your happiness so high if not electron affinity school so actually I love my electrons it's about high ionization energy if I have hyonization energy I love my electrons and I will fight you are not going to steal it if I have high electron affinity I want your electron badly so because okay let us do small rest we're going to talk about is metallic Behavior so you know what I know that we know that um we have a non-metals here and metals here and those are metalloids but actually you know what if we look at periodic table our properties will change step by step so it's not like border metals non-metals our purposes change step by step so metallic character or metallic Behavior will change will will change like it's shown in in this small periodic table so here helium will have uh hilum has non-metallic Behavior and fluorine let us say chlorine and francium has the best metallic Behavior metal behavior is connected with low ionization energy so that is why metals are easy loose electrons and form cations okay one is one let me I illustrate this in in this reaction when iron and iron is metal reacts with oxygen product will be rust iron 2 or 3. it is by the way balance this reaction okay if it's oh if it's an odd make it even I see odd make it even for three well done but look at this our iron was Zero oxidation number of iron was zero and our iron in compound in my rust is plus three so I see that my iron is loser of three electrons loser reducer oxidized and we know that and we know that reducer is the same as reducing agent okay so when metal react with non-metal to form ionic compound metal acts as reducing agent agent reducing agent also to show you how yeah you you don't have this I just add this I actually I always do this but I write it down now I have it so you just need to rewrite I also also want to show how properties change how properties metals and non-metals change in in an example of oxides so can you see that sodium oxide magnesium oxide aluminum oxide sulfur oxide so all these oxides are compounds is our elements with oxygens and I if you look at sodium Magnum magnesium magnesium and aluminum so you see that all these guys in one period but I can tell you that sodium is metal and uh chlorine is non-metal non-metal so we have like transition in metals form basic oxides basic and non-metals form acidic and you will see how it changed from metal basic and non-metal acidic okay when my basic oxide reacts with water it gives me sodium hydroxide which is deal it as a balance so okay one one two two one two okay we're good we're both magnesium hydroxide reacts with water also also gave me magnesium hydroxide which is base okay let us balance it okay it's it it is balanced already okay one two okay good I'll so this is also basic my aluminum hydroxide aluminum 203 is amphoteric um amphoteric means not acidic not basic both see dick and basic aluminum 203 is can be said main component of clay and you know that Clay is not soluble in water but aluminum oxide can react with acids and base and in this we can see that aluminum hydroxide has acidic and basic properties okay if it reacts with acid it will form aluminum cl3 plus water let us balance two aluminums two aluminums and um six will be six and I should have three Waters if my aluminum reacts with base so this is a bay this is acid base it will form complex compound it is a sodium aluminum o h four types so still we have some reaction okay let us balance um two aluminums I put two here now I have two sodiums I put two here now let us count uh hydrogens uh how many hydrogens do I have here four multiplied by two eight hydrogens two hydrogens here I need six hydrogen okay balanced my so you see that this guy is amphoteric silicon oxide is sand for sure you know that sand will not react with water scent is not soluble in water and this guy is slightly acidic silicon oxide do not react with acid but it will react with a base and it form sodium silicon or stream and what what is our and water so let us balance it sodium to surgery okay so we have two one two three yeah done get balanced Bells and now my uh phosphorus oxide with water will give me phosphoric acid a h3po4 let us balance four phosphorus I will put four here and and four multiplied by three twelve so I need to put a 6 here so four multiply before 16 Oxygen 16 oxygens balanced so you see that this is acidic because it produce acid then my SO3 also acidic it it gives me h2so4 yes it's balanced already here I have per chloric acid h c l o four two let us see if it's balanced yes it's balanced so I want you to show this let us go through this so can you see that we start with something extremely basic because it it forms base and we finish with something very acidic which gives us very strong acid and a sodium to chlorine they are in the same period so you see that properties change in periodic table okay and one last example of how properties change periodically boiling point of neon boiling point so BP is boiling point by the way um MP it's melting point if you see somewhere okay boiling point of neon is negative 245.9 degrees Celsius a boiling point of Krypton is negative 150 2.9 degrees Celsius we want to know we want to estimate what is boiling point of argon I noticed that I neon encryption they are here in periodic table neon encryption and argon is in B because I know that all properties change step by step I can deduce that argon will have boiling point average let us estimate it so boiling point of argon will be negative 245.9 Plus negative 152.9 degrees Celsius and divide by 2. delete so a negative 2 or 240 5.9 minus 152.9 here my number is 3 negative 3 98.8 and divided by two so uh my boiling point estimated of argon is negative 199.4 degrees Celsius sure it's it's not exact number but it should be pretty pretty close prediction just because I know that all properties will change periodically and step by step and one more piece of information because you you might have this an exam we learn that we have alkaline Earth's Metals in group 1A we learn that we have oh ah 1A alkali metals 1A alkaline alkali 2A alkaline Earths metals eight a noble gases halogens we know transition metals I want you to know one more categories of elements those are rare earth metals and they are candium youth room and lutacion and Lam lanzanites if you look at this periodic table these guys and these guys so because in in exam you might be asked is let us say samarium rare rare burst metal and you need to say yes that is it ah the funny moment is that they are not rare actually scientists very often make mistakes because you see they thought that those elements are rare but after a while they found that a lot of these elements these metals so but I want you to know this category okay we are done with lecture

Transcript for:Chem Unit Four Video 3

Transcript for:
Chem Unit Four Video 3