hi friends let's start with a chapter called periodic table it has the roots of the ninth standard which need to be powerful then only i expect you all to come to this tenth and have the audacity to study with me so first go back to the ninth standard make your base strong and then come to the ten standard right however um i know my students very well so i don't expect anything from them much so i am definitely gonna give you a brief about the ninth as well then only that connectivity will be formed for the ten standard and that foundation that base will be built um in ninth standard it all started from three people mendeleev doberenial and newland they were the ones who started with the positioning the locationing of the elements in a particular format not in a table though but in a particular format [Music] so if i happen to talk about this chapter periodic table all right just skipped out guys the weightage of the chapter from the board's perspective is approximately seven marks yep and as i said how did this periodic table come into existence yep it all was started with first doberania second new land and third mendeleev come into existence okay so first dobber in here second i'm newland hi students i'm newland i am going to arrange the elements again in the increasing order of atomic weight atomic mass the speciality of my table is the elements are arranged in increasing order of atomic weight yes and every eighth element eighth element shows similar chemical properties to the first element then came mendeleev hi guys i'm ending leaf what i did was i also arranged the elements in the increasing order of atomic weight increasing order of atomic weight but i gave a table in the table there are rows horizontal called periods there are vertical groups called columns yeah and i am arranging the elements in a tabular format so these were the three people who failed miserably the same mistake all three of them made and it was it was this all of them arranged the elements in the increasing order of atomic weight atomic mass that was a problem then came the person called mosley mosley saw there the the failures the drawbacks the limitations of all three of them he changed the concept he said fine the table looks nice it sounds good let's now arrange the elements in the increasing order of atomic number that is z atomic weight is represented by capital a because we know atomic weight is the number of protons plus neutrons and atomic number is nothing but just protons or electrons so mostly change the dimensions of placement and then this was a bit more you know polished and made restructured into a periodic table so mosley's periodic table was actually the successful one and in mosley's periodic table let's study the salient features so the salient features of the modern periodic table or a derived form a derived form of mosley's periodic table is as follows first the elements were arranged in the increasing order of their atomic weight so increasing order i'm just writing the briefers atomic weight no atomic number what weight atomic weight was a flop show by them come on ah you're sleeping over it come on yes atomic number not mass number the second pointer there were seven rows rows are always horizontal students and they were called periods and there were 18 18 columns they are vertical and they were called groups so this was how a structure of a table was all right now remember since the elements are arranged according to their number of atomic number that's the number of electrons electrons we are talking about the electronic configuration so i can say the table was based or it was dependent okay the location the position of elements was dependent on the number of electrons that is electronic configuration there were many nice properties the table showed it showed just giving your brief a reference these horizontal are periods and these are vertical columns so these are columns and these are rows periods now remember the speciality of the placement was down the group down the subgroup in a column the elements which were placed which were positioned they show similarity in the chemical behavior chemical behavior that means when they react their behavior almost remains very much similar to each other for example for example you take a metal you take a metal you react it with a dilute acid of course what is formed a salt and hydrogen so can i say that you take any dam metal yeah you react it with a dilute acid majority of the time the characteristic feature remains the same you are going to get a salt of course a different salt and hydrogen gas so can i say down the group the chemical behavior the chemical properties of the elements were similar across the period across the period this way horizontally left to right the elements were uh were differing by chemical nature yes for sure but they had the same number of shells now what's that okay that's the significance so if i happen to talk about first the significance of a period period means row horizontal what's the significance of the period elements in the same period elements which are in the same period they have same number of shells that is the number of shells remain the same so if you have an example if you have taken example sodium magnesium aluminium it goes on up till argon okay can i say the configuration of sodium is 281 it has three shells magnesium 282 argon 288 can i say in this row horizontal period each of the element has how many shells three shells that's the significance of a period all right if you talk about the significance of a group that is column first the valence shell config configuration remains the same now what what do you mean by that i'm not understanding i'm sorry i'm sorry nice one this is check this guys i can say in the first group in the first group you have hydrogen lithium sodium potassium rubidium caesium francium there you go for it francium is a radioactive element i'm going to discuss about this after some time just taking an example to explain this concept configuration valence shell configuration check one electron in the last shell one electron in the last shell one electron in the last shell now that's monotony can i say in the example i've taken down the group check it down the group can i say the last shell each of the element has one electron and it is equal to the column number this is column number one roman number one a group number one that means the elements which belong to the first group i'm gonna draw the table you know in a moment hold please okay the elements which belong to the first group have one electron in the outermost shell that means that is called valencia the configuration remains the same down the group they show similarity in the chemical properties so similar chemical properties this was the significance the importance yeah the importance of a of a group so this was just a base a brief for the nine standard right from the nine standard perspective then standard we're going to talk about a bit more in depth about the periodic table however if i talk about the salient features right it was that the table okay the table which was made the periodic table there were few properties which were studied there were few properties which were studied and those properties were like atomic radius ionization potential uh electron affinity electronegativity yes metallic and non-metallic nature so based on the positioning of the elements based on the location of the elements we study we are going to study about all these five periodic properties what do you mean by periodic when i'm talking about the word periodic it means after regular intervals of time that means can i say as we go ahead and then we come down can i say after regular intervals of time there is some sort of a similarity in properties and those periodic properties we're gonna stay we're gonna study we're gonna have a glance and we're gonna by heart it in a while talking about the actual periodic table let's begin guys check i'm not going into super depth but yes much of a depth okay so now the periodic table looks something like this i'm gonna go a bit fast with it yeah that's what it looks like buildings a set of buildings this is called group one group 2 group 13 14 15 16 17 and 18. start learning with me again apart a portion uh it's of nine standard right but you should know it we also call it as roman 1a roman 2a roman 3a 4a 5a 6a 7a and 0 group 0 we come to it out here we have the groups from 3 to 12 or roman number 1 b b to 7 b and 8. that's how it goes yeah now first thing these group a elements okay having a quick review group a elements are called normal elements so if i talk about group a elements we call them as normal elements and group b elements we call them as transition elements now what is the difference between them normal elements consists of metals non-metalloids and non-metals however the transition elements out here they consist of weak metals only metals a bit weak in nature okay first second point normal elements this and all of these the normal elements only the last shell okay the last valence shell is incompletely filled however for all these nor all these transition elements out here the last and the second last that is the valence shell and the penultimate penultimate shells are incompletely free so these are two points of differentiation between normal and transition elements if i fill the table guys yeah let's say this is your this is going to be your period one so period one period two right then we have period three period one period two period three we have then period four period five period six and finally period seven in period one you have hydrogen hydrogen can also be a part of halogen 9 standard hydrogen chapter and we have helium inert duplet stable then we have lithium we have beryllium we have boron carbon okay after carbon we have nitrogen oxygen fluorine and neon after neon we have sodium okay after sodium come on magnesium you know it you know it aluminium silicon phosphorus sulfur chlorine argon after the argon we have calcium i'm sorry potassium k calcium potassium this is k and calcium uh calcium is the 20th element so i can say this is the 20th element and i all i need from you all to know is the 20th up till 20th element also i want you to know a few more apart from this we have hydrogen lithium sodium potassium rubidium caesium francium where francium is radioactive in nature out here in the 17th group i want you to remember a few more fluorine chlorine bromine iodine astatine and no need to remember this one helium neon argon so we have krypton xenon read on and you don't need to remember this so this was about the normal elements and the transition elements which i have written right and we have seen the differentiation between both of them all right so these are the elements which i've written on the board should be bi-hearted all right after this guys we're gonna study about the number of elements in the first period we have only two elements hence we call it as the shortest of the period we have eight elements in the second period eight in the third period eighteen in the fourth period eighteen in the fifth period six has 32 elements and period seven has 26 elements now this is a thora slightly you know um an antiquated sort of a periodic table however even period 7 now has much more elements as what i have written all right so if i talk about the shortest and the size i've spoken about the numbers period 2 and period 3 together they have the same number of elements they are said to be short periods period 4 and period 5 are stated to be long period even period 7 is a long period and period 6 is the longest of the period so guys which is the longest period it is period 6 consisting of 32 elements and period 1 is the shortest of the period consisting of 2 elements now usually kids tell me sir there are 18 columns so obviously in period 4 there are 18 elements period 5 there are 18 elements all right period 6 sir are also 18 elements right then how did you write 32 how is it possible i tell them nice question listen at the bottom of the series we have a continuation of period 6 and period 7 so we have period 6 we have period 7 consisting of 14 elements each so out here guys in this period this one there are 18 elements out here 18 of them 18 plus 14 makes it 32 that's how you have 32 in the 7th period out here you have 12 elements 12 and 14 out here makes it 26 elements that's how we get 32 and 26 has the number and these two periods or these two rows which are placed separately at the bottom of the periodic table are called inner transition elements and there is a special name given to it so can i say the inner transition elements are the two periods six and seven a continuation and they consist they consist of lanthanides which are also called rare earths and we call the period 7 as actinide also called it as radioactive elements all right starting from cerium to lutatium lutasium or lutatium i wish cerium to lutation and thorium to laurentium this is the start and then no one's going to ask you but just just remember it right so this was about the inner transition elements which are also called the radioactive elements right guys so all of you all till now this was a briefing about the periodic table now if i talk about the first group down the group i know that the valence shell configuration remains the same and we have studied about the significance of a column of a group right with this now always remember one thing students if i talk about the first group we have the first one we call it as alkali metals so group number one are called alkali metals group number two is said to be alkaline earth metals these are transition elements from 13 up till 16 we call them as poster transition elements 17th group is said to be halogens and 18th is said to be inert the zero group so always remember students if i happen to ask you a differentiation between any of these i'm gonna give you a quick pointers first one come on alkali metals let's consider sodium as an example can i say sodium is a very very very active metal point number one second the valency is one one plus to be more precise because sodium gives away one electron it gives away an electron it becomes electropositive it is a reducing agent because it gives a negative power to someone else so it undergoes oxidation rise up right and and so i can talk about the valency the electro positivity then we can talk about a very active metal reducing agent undergoes oxidation okay so these are all the properties of alkali metals and also alkaline earth metals the same properties because the same properties because they both are metals if i talk about halogens the 17th group they are electronegative because they accept take away the electron right they take away an electron and they are they become negative they get reduced they are oxidizing agents and the valency is one minus you can say that is the oxidation number one minus for the halogens inert gases on the contrary inert gases right they have zero valency why zero balancing because they're stable they don't want to take share or give or you know there is no transfer of electrons because they are or they are already stable right they have octet or duplet so they have zero valency they are not reactive under normal conditions of temperature and pressure transition i've already spoken about normal i have already spoken about the post transition elements these ones group 13 to 16 consist of metals metalloids and non-metals they consist of everything every damn thing the first two consist of metals only 17 consists of non-metals so this was all about the generalized concept of non-standard periodic table now talking about the periodic properties and the bridge elements two new things so first if i talk about the bridge elements i give you an example to explain this concept we usually talk about period number two and period number three in order to explain this concept listen in period two i have lithium starting yam and lithium we have beryllium we have boron we have carbon we have nitrogen yeah come on yeah this one lithium beryllium boron carbon nitrogen oxygen and so on just underneath the lithium we have sodium magnesium aluminium silicon phosphorus sulfur and so on always remember the bridge elements are those elements which have a diagonal relationship i'll tell you what do you mean by a diagonal relationship now can you see these are all diagonals which i've made you know what in in a geometry or right isn't this said to be one of the diagonals of course yes so what's a diagonal relationship guys remember if you talk about period 2 and period 3 these elements which are diagonally placed they show similarity in the chemical properties now we very well know that if you go down the subgroup the chemical properties are similar that is for sure it goes without saying but but there are few elements in period two and period three which show even a similarity in the chemical nature hey lithium it is like magnesium hey this beryllium is something like aluminium much love the properties are very much similar of magnesium with lithium aluminium with beryllium all right so even there is a diagonal relationship so if i happen to write in short in the exam first i need to draw this and and show this this representation and i can say i can say that there is a diagonal relationship diagonal relation means what it means that there is similarity in chemical properties diagonally diagonally please all right so this was about the bridge elements now if i talk about the periodicity in properties we are going to first study about atomic struct atomic radius then we'll be studying about um the second property is ionization potential we'll be studying about electron affinity electronegativity and finally we'll study about the metallic and the non-metallic nature so now let's study and start with atomic radius as the first periodic property right so till now what we have done is the main chapter starts from here this the periodic properties this was all just a briefing of nine standard a quick review of ninth i have done with you you should know the basics right now remember while speaking about all these five periodic properties i am gonna take an example of the second period or the let's take example of the third period this one and the first column so i am repeating what i spoke in order to understand okay to to just you know analyze the periodic properties i am going to take an example of the third period and the first group and whatever i'm gonna speak that pattern right that theme remains the same for all periods and for all groups always remember right so just go through this all right please nine standard as i said you need to know it we jump to the tenth the atomic radius let's start with atomic radius the first periodic property i'm just writing short ar atomic radius atomic radius just check i'm drawing a diagram this is a nucleus henceforth i will call it as mother nucleus mom mom loves students mom loves kids mom loves their children so this is mother nucleus having neutron proton let's say this is the innermost shell the k shell the second shell i'm just making two shells okay if i uh define what's atomic radius it is a distance from the center of the nucleus to the outermost shell so can i say atomic radius is the distance from the center of the nucleus to the outermost shell outer most orbit that's what atomic radius is remember that first thing okay it is measured in unit called angstrom unit we call it as a naught this is the unit of measurement of atomic radius now let's study about the trend the trend the the pattern as we go from left to right in a periodic table what happens to atomic radius does it decrease remain the same or increase uh so henceforth please please repeat with me i'm gonna speak in this way as we go across the periodic table from left to right how is the nature similarly down the group as we go down in a periodic table from top to bottom what will be the nature all right what will be the character of the atomic radius how will it be affected that's what we are going to study now all right let's start so now please remember one thing the terms which i'm going to use nucleus is mother mong if i talk about electrons these are children these are kids okay we are going to study in that reference okay there is something also called as nuclear charge before i jump to the concept let's see what is nuclear charge let's understand this terminology nuclear nuclear means coming from the nucleus charge charge means can i say uh something like positive negative yes charges you know what charges are so nuclear charge is nothing but a force of attraction a force of attraction a bonding a linkage electrostatic force between the nucleus and the electron it is a pulling effect okay so if i say there is more number of neutron protons obviously if there are more protons there are more electrons so protons increase electrons also increase because don't we know that an atom is stable it is electrically stable that means in an atom the number of protons and the number of electrons are the same right so if there is a rise in the number of protons there will be an equivalent rise in the number of electrons you know that right we say the nuclear charge increases nuclear charge means the pulling effect the force of attraction between the protons and electrons there are more in number more in magnitude it increases so keep it very simple if protons increase then obviously the electrons will also increase and i can say the nuclear charge increases remember this is like a base everything increases a direct proportionality people right so let's study about the nature of atomic radius across the period and down the group i told you i'm gonna study i'm gonna take an example of the third period so in the third period we start our game we have sodium magnesium aluminium goes on second last element is chlorine and then we have argon so if i talk about the electronic configuration listen to me very very very carefully check we start across the period from left to right in a periodic table can i say the number of shells remain the same we just made a small error to eight eight yeah the number of shells remain the same this sodium has three shells three shells three shells three shells so ideally can i say uh like clay man that if the number of shells are the same the atomic radius should be the same right but sorry no it is not the same look what happens as we go from left to right can i say ideally atomic radius should be same ideally but it is not the case first pointer second pointer uh i say that the number of protons and the number of electrons increase come on here it's increasing can't i see one two three four five six seven eight the number of electrons are increasing so the number of protons are also increasing so can i say the nuclear charge also increases oh come on nuclear charge has increased nuclear charge increases if nuclear charge increases the pulling effect the attraction closeness increases protons more protons will say a electrons come to me look there are more children the number of children kids in the outermost shell are increasing mother the mother nucleus calls the child hey come son kids all come please come eat food go mom loves the kids yeah mom loves their kids so can i say that always remember the nuclear charge increases the pulling effect increases so nuclear charge increase force of attraction increase and therefore the atomic radius decreases so guys look at my gesture sodium magnesium aluminium chlorine argon oh what i did look at this big small small small small small big in general yeah that's an exception wait now i know you have been inquisitive about what's going on but can i say in general as we go from left to right in a periodic table the atomic radius decreases because the force of attraction increases the pulling effect increases and and obviously when the pulling effect increase come on they they love each other they come close to each other a bond is developed they become small all right now that exception out here when i went i suddenly increased the size check that's an exception argon okay argon this is the basic atomic radius decreases this is my answer but what i'm writing is an exception okay argon is big in size reason what is the reason reason number one argon is electrically stable can i say argon is inode it has two eight eight electrons and it has octet stability octet stability therefore the electron electron repulsion is more now listen to me in argon the mother nucleus okay the mother nucleus there are eight children in the outermost shell mother nucleus tells hey kids come to me all right we'll eat together now these kids are useless hopeless kids what these kids do they fight amongst themselves it's stable they have a lot of money they have that egoism that power that useless power of money i don't like that but these eight kids they fight we won't eat with him this kid says i'm not gonna eat with him he says oh come on get lost i will eat in my own room so guys can i put it this way these electrons which are negative they will have an electron electron reposition so despite mom calling them together that come attraction no these these electrons these kids they don't listen to the bone and because of this electron electron repulsion they try to move away from each other so when they move away atomic radius increases so two reasons reason number one stability of argon and reason number two reason number two is the electron electron repulsion so always remember because of these two reasons because of these two reasons the problem is the last one has slightly more atomic radius as compared to the others right all right let's go down the group let's go down the group so down the group i talk about the first group when i explain the trend remains the same for every period and for each group please okay atomic radius down the group uh group number one we have hydrogen lithium sodium uh we have potassium rubidium cesium francium now students francium now is radioactive this is radioactive so usually most of the teachers they don't consider francium into the competition it's cheating now it's cheating yeah these all people are normal and this is strong so that's not fair deal so people we stop at cesium and we will discuss up to cesium only okay down the group what happens check this is more beautiful hydrogen has one shell one one orbit lithium has two orbits sodium one two three as on cesium it is in the sixth period a come on hydrogen is in the first period so it has first shell lithium in the second period it has two shells sodium in the third period it has three shells cesium is in the sixth period so it will have six shells one two three four five six shells oh come on look at this as we go down the group can i say the size is obviously increasing it's very common sense but look at my explanation i will confuse you check answer to my questions come on down the group number of protons are increasing of course they are of course man this has one proton the configuration is 2 1 2 8 1 this is 2 8 something something something something one right with this check this as we go down the number of protons and electrons are increasing so if the number of protons electrons increase the nuclear charge also increases yeah we've seen that so i will say protons increase electrons increase nuclear charge increases perfect so if nuclear charge increases the pulling effect also increases hey come close children let's have a bond together so because of the pulling charge ideally the radius should decrease atomic radius should decrease because of the nuclear charge increase are you understanding what i'm saying think it's interesting don't sleep okay so atomic radius also decreases atomic radius should decrease should decrease but remember one thing the number of shells are increasing oh god there was one shell two shells three shells so there is a rise in the number of shells so i can say that this is this is not good here listen the second point is number of shells are increasing so now this is a contradictory effect a contradictory effect one of the factor is trying to decrease the size other factor is trying to increase the size listen num number of shells number of cells are increasing if the number of shells increase and because of this radius increases but the number of protons electrons in charge is increasing so force of attraction is increasing the force of attraction is increasing thus the radius is decreasing that means this factor tries to increase the atomic radius this factor tries to decrease the atomic radius so look at my gesture let's see who wins the competition it is a contradictory effect check my gestures properly this was hydrogen look at my hand the size this was hydrogen lithium one shell increases but cooling effect increases so it will shrink sodium one shell increases but pulling effect increases slight shrink so tell me though there was a shrinking effect there was a pulling effect but wasn't the pull small so basically the pull could not win the pull could not defeat dominate overcome the number of shells the effect because of number of shins so i can say this because of the rise in the number of shells there is a vast increase in the size and because of the nuclear charge there is a small decrease in the size so basically if i go down okay and average it out the resultant is that the size increases so i can say number of shells win the game the number of shells dominate over dominate over the nuclear charge and therefore the atomic radius increases so now guys if i happen to summaries summarize it out okay remember a summary to be written out here across the period atomic radius decreases and down the group atomic radius increases this is the summary and if you ask me sir in the entire periodic table who is the smallest element and the smallest element having the smallest radius is helium and who is the largest element the largest of all elements having the largest atomic size ideally it is francium but you can see it is cesium so now this is a contradiction it can either be francium or cesium i'm repeating the one the element having the maximum size okay maximum atomic radius is actually frenchium but as i said francium is radioactive in nature so we can consider it out to be cesium right with this so this was all about the first periodic property which is atomic radius go through it and we shall compete with the next one ionization potential the next concept the next periodic property ionization potential all right ionization potential all right what exactly it is check first i'm speaking the definition it is the amount of energy required to release release remove an electron from the outermost shell of an isolated gaseous atom weight it is the amount of energy required to remove an electron from the outermost shell from outermost shell of an isolated gaseous atom let's understand this if i'm talking about a mother nucleus neutron proton and if i'm talking about uh let's make three shells and understand the concept right i'm just making the electron in the last shell the final shell the valencia now this is the electron let's pick up a story this is mom and this is sun mom loves the sun very much hey son come and eat food mom talks to the son son is not very much interested he doesn't give a damn about the mom not a good son not a good son now listen mom has good chapati mom has cooked vegetables rice okay the the nourishment the nutritious food for the sun son is not interested in eating the food now a stranger comes from outside he's a bad man he comes right so something like this he gives chocolate to the sun he tells the sun the bad man speaks haha hey son come here come to me i give you chocolates come to me now can i say these chocolate the chocolate is the energy that is the energy okay required to do what to remove the sun to remove the electron from the outermost shell of one isolated atom we're only going to talk about a single atom as of now not multiple atoms so can i say it is the energy energy out here is the chocolate given by whom given by the bad man or given by us okay to remove the electron to remove the sun from the bond of the mother from the outer motion that's ionization potential so i can say uh if i talk about the behavior from left to right in a periodic table from left to right in a periodic table so can i start with across the period taking an example of the third period again third period only now that's monotony i like that we have sodium magnesium it goes on chlorine and argon so this is 2 8 1 this is 2 8 2 it goes on up till two eight seven and two eight eight now check this all of you tell me i need to remove just one electron from this two electrons from this and eight electrons from the last one so can you tell me one thing which is easy to remove one electron that means i have to drive one child out here i just need to give him some sort of a bribe i just need to tell hey son whether it's only one child one electron one kid yes i just need to bribe him isn't this easy it's very easy so i have to supply less energy to remove one electron in contrast to this out here argon i need to supply so much energy in order to remove eight electrons so in which case the ionization potential the energy required be more can i say argon so as i said across the period from left to right number of protons and number of electrons increase therefore the nuclear charge in board exam you can't write nc but out here remember nc stands for nuclear charge okay the nuclear charge increases if nuclear charge increases energy required to remove the final electron the electron in the valence shell also increases therefore amount of energy increases and i can say that the ionization potential also increases so across the period from left to right we need more energy we need to supply more energy in order to remove the final electron the electron in the valence shell thus ip increases okay let's study down the group down the group again hydrogen lithium sodium potassium rubidium caesium frankie i'm not talking about please come on this is 1 this is 2 comma 1 this is 2 8 1 it goes on now answer to my simple question in all of them if i draw a simple shell neutron proton hydrogen one electron in the outermost shell cesium six shells one two three four five and six all right one electron in the outermost shell if you check the comparison between both of them answer to my simple question isn't the atomic radius very small in case of hydrogen so the atomic radius is less out here the atomic radius the distance between the mother and the sun is so huge so far there is no force of attraction there is no strong bonding the mother is not able to control this child because it is so far from the child so can i say this child is far it's not getting love of mother this child is under the influence of mother's love so can i say the bond the love between mom and child is awesome out here awesome no love no no care concern so can i say the chances of this child getting swayed by energy by the chocolate is very easy okay if you supply a chocolate to this child can i say this child will easily be lowered by the chocolate yeah so isn't it very easy to remove this electron from the outermost shell it is difficult to remove this electron because if i talk in technical language atomic radius is less there is a good force of attraction out here the force of attraction electrostatic force of attraction is less and if the force of attraction is less ionization potential is also less you can easily remove this electron by supplying less energy and out here out here you need to supply more energy to remove the electron in the outer motion so basically if i happen to summarize it guys ionization potential down the group decreases you need less energy as we go down so if again a summary as i said okay in a tabular form across the period down the group can i say across the period the ionization potential increases and down the group ionization potential decreases now if you're asking me that which element has the maximum ipn which has the minimum ip i will say guys the minimum minimum ionization potential the element is cesium so i can say the least ionization potential is with cesium reason check cesium the child is very far from the mother so you can supply less chocolate less chocolate means you can even give him an eclair okay a simple eclair and still still the child is gonna leave the shell leave the orbit and go with that stranger for that chocolate for that energy so can i say the energy supplied is very very very less the greed is less so i can say it's very easy to remove this electron from the outermost shell of cesium because the force of attraction is less between the nucleus and the outermost electron and the electron in the outer moisture and the maximum ionization potential maximum ionization potential the element is helium helium first of all it is stable duplet it has two electrons in the outermost shell and those two electrons first are stable also they have a lot of money i don't give a damn about chocolate yeah come on i can buy an entire chocolate house by myself that's what helium electrons say and the second thing is they are close to the nucleus if they are close to the nucleus the force of attraction is tremendous so helium you need maximum energy in order to remove the electrons from the helium atom and minimum energy to remove the electrons from the cesium atom so this was the concept of ionization potential the bad man concept yeah hope you've understood any any doubt you can just let me know for sure the third periodic property electron affinity we call it as ea all right electron affinity it is the amount of energy released released when an electron enters enters comes into the outermost shell of an atom and it becomes an anion to become an anion to make it an anion now this is exactly a contrast to ionization potential listen now there is again that mother nucleus mom nucleus and the outermost shell you remember the sun had left the orbit in ionization potential the bad man came he offered chocolate to the sun and the sun he took the sun away with him now the sun realizes i miss my mom i want my mom i want to go back to my mom so mom puts a condition mom puts a condition listen son if you want to enter back into the orbit if you want to enter the electron needs to enter back into the orbit can i say the energy has to be released the energy has to be released so now an electron comes and enters into the orbit he needs to take away give away okay leave that greediness okay leave away that ex greediness the factor okay which he had taken so i will say it loses there is a loss of energy there is a loss of chocolate and finally the electron can enter into the outermost shell so you can correlate it that way so it is the amount of energy which is released for an electron to enter into the outermost shell of an atom and when an atom accepts an electron it accepts an electron obviously it becomes negative in charge we call it as an anion cations are positively charged ions and ions are negatively charged ions so this is what electron affinity is simple language the need the thirst the want of electrons simple all right okay the pulling effect of electrons that's electron affinity if you talk about the the property the nature across the period behavior across the period let's see it so across the period from left to right we're gonna always speak about the third period so we have again sodium magnesium aluminium and so on chlorine and we have argon 288287 281 now answer to my simple question there is an electron out here electron is flowing an electron is coming in its path where will electron prefer to go who will pull the electron stronger can i say chlorine will pull this electron more strongly reason is reason is it needs one electron to become stable sodium needs seven electrons to become stable so obviously the pulling effect the power of chlorine in this in this row in this series which i have written is the maximum so can i say the pulling power of electron the affinity the liking of electron is more shown by chlorine in this period so i can say as we go from left to right the electron affinity increases because the nuclear charge has increased the pulling effect of electron increases so i can say across the period from left to right yes across the period from left to right nuclear charge increases the pulling effect of electrons increases and i can say therefore electron affinity increases from left to right okay let's talk about down the group one more thing argon has zero electron affinity because it doesn't want it is already stable electron can never never go to argon so i can say the inert gases have zero electron affinity they have zero electron affinity fine talking about down the group down the group all right first again hydrogen lithium sodium potassium rubidium caesium okay fine now one electron has is coming now i very well know i very well know that one electron will be accepted by none of them because obviously now if they accept one electron it will do no good because even if one electron enters into lithium or cesium can i clearly say they are still not going to be stable so ideally i should explain it using the halogens that's more precise so let me take the 17th group to explain my concept more vigorously so i'm talking about halogens now so we have halogen starting from hydrogen may be a part of that group not always we start from fluorine chlorine bromine iodine acetylene and so on tell me one thing 27287 it goes on tell me one thing who is closer to the mother nucleus obviously fluorine it has only two shells chlorine has three shells one two and three so tell me one thing the atomic radius of fluorine is small the atomic radius of chlorine is big the force of attraction force of attraction in chlorine between the mother and the sun is hard is strong because of the small atomic radius so tell me which will have a more pulling effect i think it has to be fluorine fluorine will easily pull an electron will easily pull an electron okay to become stable because of the high high electron affinity the liking and the closeness because the atomic radius is less and as we go down the pulling effect the pulling power decreases because the electron the shell starts getting far far means the force of attraction decreases so i can say down the group down the group electron affinity decreases so electron affinity decreases down the group so if i happen to now analyze summarize it goes this way across the period across the period the electron affinity increases and down the group the electron affinity decreases yeah that is the whole ideology so we have seen that if in one of the context if it increases the other context it has to decrease so if across the period something decreases down the group it has to increase and vice versa it's always going to be a different behavior inverse proportionality remember across the period and down the group everywhere okay so if i now if you ask me sir which element has the maximum electron affinity and which element has the minimum electron affinity so i can say the minimum pulling power minimum pulling power is of caesium cesium first of all this one electron is far from the mother nucleus in cesium one electron there's only one electron in the outer motion and that poor kid is so far from the mother mother cannot control that poor kid how is it gonna control one more kid who is going to enter the orbit please please understand understand in the cesium if i make the outermost shell this is the sixth orbit the mother has no much of attraction no control over her single son over the single son if she can if she can't control the sun how on earth how the hell is she going to control a new son who is going to enter the orbit yeah so it's not possible so cesium has the lowest electron affinity minimum and the maximum pulling power come on i want to become stable electron it's always in hunt where is electron where is electron do you have an electron and that is nothing but fluorine so fluorine has maximum electron affinity and cesium has the minimum electron affinity so this is a concept which is contrast to ionization potential and after this two more properties left just go through this thoroughly we start with electronegativity you will say it is fluorine because fluorine here you have done flooring has the maximum pulling effect as compared to chlorine so you will write it is fluorine and i will say wrong yes now this is the catch this i was waiting for guys your concept what i have taught out here is perfect there is no harm to it now look at the exception it should have been flooring the maximum pulling power undoubtedly i have taught the same thing out here but the answer is chlorine now this is a twist it's like a movie check this this is an exception exception ideally it should have been fluorine but no it is chlorine look at the story what happens so now we have this electron back this electron is flying it is pulled the tendency of pulling is maximum by fluorine undoubtedly i am not having any second thoughts over it so this electron is actually just just see it's flowing chlorine is pulling it fluorine is pulling it the victorious person has to be fluorine because the pull of fluorine is much more than chlorine lovely so mother is calling sun come please i love you the sun is coming coming coming coming coming but the house is very small the atomic radius is very small and already there are seven electrons sitting in the house there come on fluorine two comma seven there are already seven electrons present so when this electron flows the other electrons the other children are nasty ones they don't let this electron to enter so there is no place because of electron electron repulsion and because of a small atomic radius so this is a problem the atomic radius of fluorine is small yes yes mother calls the sun with pure love the force of attraction is good enough but there is also a force of repulsion because of the other electrons and because of the small size are a man we don't have place in house and how can you join us so then the electron goes to chlorine so guys the electron actually settles down out here because chlorine the atomic radius is high and electron electron repulsion is low because of the size there is more space in the family to accept one more child there is more space so my answer is not fluorine this is an exception please it has to be chlorine so the element having the highest electron affinity is chlorine but the maximum tendency of pulling is fluorine fluorine almost won the race almost but the the other nasty kids didn't allow it to reach the final destination right so this is a beautiful concept so just go through this and we start with the next periodic property which is electronegativity the fourth periodic property is electronegativity electronegative now electronegativity is the tendency of pulling the electron okay by an atom by the nucleus in the outermost shell so it is nothing but the tendency t e and d and c i just forgot the spelling of tendency sorry it is the tendency to pull an electron or in my language can i say it is the easiness it is the easiness with which an electron enters into the outermost shell it is the easiness with which an electron enters into the outer motion in the valence shell now it's very simple if i talk about electronegativity and if i go across the period if i go across the period again sodium 281 chlorine argon tell me one thing if an electron again tries to enter where will it prefer going of course it will prefer going to chlorine because chlorine can easily pull an electron and become more stable so across the period who has the more tendency to pull the sun give more affection and love it is the chlorine so therefore can i say the electronegativity across the period increases increases now some students ask me sir what is the difference between electronegativity and electron affinity look electronegativity is the process it is the property it is the tendency it is the inherent characteristic of a body the virtue of pulling someone now say for instance for example i okay i look good yeah i have the tendency to attract people and so i am quiet i'm not speaking anything i just look good and just i i observe that person the person is attracted towards me that is electronegativity the tendency of pulling but as soon as i open my mouth and i am hopeless at speech i speak something like hey how i know oh come on that person is just gonna turn and go somewhere else that is like electron affinity i know it is a stupid example but i know you're gonna remember such examples i know my students very well so if i okay have the tendency to pull that is electronegativity but the person is approaching me he's approaching and when he speaks to me i say how are you what are you doing my voice is hopeless right my expressions are are tremendously bad okay derogatory the person takes a u-turn and goes to the other person and that is chlorine just like electron affinity so electron affinity is when an electron actually enters actually enters and this is just a property of pulling the property of attraction all right so electronegative negativity across the period increases or decreases increases the pulling effect is more down the group get down the group if i talk about the electronegativity right from hydrogen up till cesium again the same explanation like electron affinity okay down the group can i say as we go down the atomic radius increases nuclear charge increases pulling effect obviously increases yes but since the size since the atomic size increases the distance between the mother nucleus and the outermost shell is more if the distance is more radius is more can i say that electron will not be much attracted much pulled by the mother because of the high distance so i can say down the group the pulling effect the pulling power decreases so electronegativity down the group decreases and across the period increases so if i happen to general generalize the concept it goes this way down the group and across the period electronegativity across the period increases and electronegativity down the group decreases remember right okay after this after this which is the most electronegative element most electronegative element is who has the most tendency of pulling it is fluorine undoubtedly look the tendency of pulling is fluorine but the electron will not enter into fluorine it will you take a u-turn and enter into chlorine because of that exception you remember i i spoke few minutes back because of the high electron electron repulsion and because of a small atomic radius but but the tendency of pulling is fixed the most attractive is fluorine okay talking about the least the least electronegativity it is cesium cs caesar fine so this was about the fourth periodic property let's go ahead with the last periodic property which is metallic and non-metallic nature okay now it's very simple as i said as we go across the period what is metallic character what do you mean by metallic nature metallic nature is uh the tendency of losing an electron the tendency of losing an electron the easiness with which an electron goes out of the last shell so i will say tendency simple language to lose an electron and tendency to accept to gain an electron so this is called metallic character and this is called non-metallic character shortcuts short forms are not allowed in the board exam i'm just writing it for your convenience we need to save time it gets bugging okay so can i say tell me one thing sodium i think it has the tendency to easily lose electrons very smooth come on here take my electron and go away i want to be stable so i can say the most metallic in this period across the period is sodium and the most non-metallic the one who gains the electron fast it is chlorine so can i say across the period you need to write all those stuff the nuclear charge increases number of protons and electrons increases yes shells remain the same but i can say the tendency to lose electron tendency to lose electron decreases so the metallic character across the period decreases and the non-metallic character across the period increases all right if i talk about them down the group down the group i think down the group from hydrogen to cesium the one who loses electron very steadily very readily is the cesium because of the less force of attraction between the nucleus and the outermost electron and because of that this electron can easily be lost so i can say what is metallic nature the tendency to lose electrons freely easily is more metallic it's said to be more metallic so i can say cesium is the most metallic characteristic cesium has the most metallic nature okay in in case of elements if i don't take francium into consideration so i can say down the group the metallic character increases and the non-metallic character decreases because if i take an example of fluorine chlorine bromine tendency of pulling an electron decreases chlorine we just did it electronegativity fluorine has the most power to attract and pull the electron now that's a different story that the electron goes to chlorine but the pulling power is of fluorine so can i say the non-metallic character decreases fluorine maximum chlorine less and so on so down the group this is what happens so if you ask me sir who is the most metallic in the periodic table it is cesium and who is the most non-metallic and i will say it is fluorine so guys this was about the metallic and the non-metallic behavior so now the final part of the chapter in which we're going to study about the neutron proton ratio and just a gist a table that how do these periodic properties behave across the period down the group with the maximum nature and the minimum nature right go through this and we go with the last part of the chapter final part of the chapter guys the neutron proton ratio the np ratio that's what we call it as now it's simple you take an example of sodium yes we call it as sodium 2311 11 11 is the number of protons or electrons and and number of neutrons is obviously 23 minus 11 so 23 represents the mass mass that means it is protons plus neutrons protons plus neutrons yep um out of which out of h protons are 11 so if you subtract so 23 minus 11 is going to be 12 so the number of neutrons is 12. all right so we have protons we have neutrons if i talk about a ratio the np ratio n is 2p i just substitute all of y'all 12 upon 11 approximately the answer is going to be 1.1 isn't this answer close to 1 close to 1 of course so i say if if the neutron proton ratio is approximately close to one we call the element as a light element we call it as a light element by mass by weight right so i will say that sodium is a light element because the neutron proton ratio is tentatively approximately very much close to the value one if you talk about another example of uranium uranium-235 92 that's the atomic number so protons the number of protons are 92 and the number of neutrons you subtract them you're to get the number of neutrons that will be 2 3 5 minus 92 that counts up to 3 minus 1 4 3 i guess yes 143 now if you take the ratio the np ratios yeah you just substitute 143 over 92 the answer will be approximately 1.5 close to that answer close to that value so i come to another conclusion that if the ns2p ratio is approx 1.5 that element that metal is said to be a heavy metal so guys if i happen to differentiate between a light element and a heavy element point number one the neutron proton ratio if it's close to one it's light if it's approx 1.5 it's heavy and we can definitely give one of the example in order to you know just prove what we spoke right now so this was the last part of my chapter the last answer to my chapter now giving you like a beautiful table a summary a gist on the five periodic properties who is the most and who is the least of each of the periodic property let's study about that in a tabular form right guys so talking about the first periodic property the atomic radius the second was the ionization potential third electron affinity the fourth one was oh come on i forgot yeah um electronegativity yes there you get it and the fifth one was the metallic nature metallic character and the non-metallic character listen the short forms are not allowed time and again i have territorial so metallic character and the non-metallic character okay i'm going to study about a gist all right across the period the variation down the group the most of them and the least of them now that will help you exactly right to analyze the entire chapter in a tabular form okay beautiful this is so making a table yes fine so talking about atomic radius come on can i say across the period from left to right the size the atomic radius keeps on decreasing so atomic radius decreases down the group the size of the atomic radius increases the most the most uh the largest of all the atoms is actually francium but i have told you all that francium is a radioactive element so we can take an element above it which is cesium so the the element having the most atomic radius is cs and the smallest size is helium that's the first one for your guys next ionization potential across the period can i say ionization potential is the amount of energy required to release an electron from the outermost shell of an atom we've done this come on so can i say an ionization potential um which element across the period can i say it's difficult to remove the electrons so you need more energy ionization potential across the period increases down the group decreases the the element having the most ionization potential maximum yep it is helium and the least ionization potential least energy is cesium the third one electron affinity when an electron enters into the orbit so electron affinity across the period across the period the affinity the liking of electrons increase a bond is formed easily and down the group electron affinity decreases the most electron affinity uh element okay the the element showing the most liking towards electron is actually fluorine yes but we know there was an exception in this example there was an exception in this answer and the answer is not fluorine it is chlorine we have studied about this i'm just having an asterisk out here to indicate this was an exception the least electron affinity cesium again fine electronegativity again across the period from left to right electronegativity is the easiness okay of attracting the electrons and definitely it increases from left to right down the group electronegativity decreases the most electronegative element is fluorine and the least of them is cesium again and the last one metallic character across the period decreases and the non-metallic character across the period increases down the group metallic character increases and the non-metallic nature decreases the most metallic most metallic is cesium and the least metallic can i say most non-metallic so most metallic is cesium and the most non-metallic is fluorine and this is vice versa right so this was a gist a summary chart for the periodic properties in a periodic table so guys this was the end of my chapter what we have studied in this chapter was first we we spoke about the uh the demerits the defects the limitations of the people who started with the locationing the positioning of the elements in a periodic table and then we were successful uh by with the help of a periodic table given by mosley then we studied about the significance the properties the five periodic properties and we studied in depth about each of the periodic property and at the end right now we saw neutron proton ratio along with a beautiful gesture summary which will just it's eventually if you do this much you've actually completed the entire chapter right so just go through this and if i happen to be erroneous at any point just get it to my notice thank you [Music]