Understanding DNF Block Elements in Chemistry

thank you hi everybody very very very warm welcome to vedanta J English Channel this is your master teacher and today we are here to discuss the dnf block chapter okay not the whole chapter of course because we are preparing for our board exams and uh this chapter and coordination compounds are the chapters from inorganic chemistry that are there in your syllabus so in today's session we are going to talk about the general electronic configuration we're going to talk about some of the general properties and we are going to talk about the position of the dnf block and why they are kept there and some other terms and you know conditions that are applied to these block basically okay all right so let's start without much further Ado because we know that our exams are coming oh once again at the door right so let's begin everybody so the first thing that comes in our mind is where exactly are this dnf block placed in the periodic table now the moment we look at the periodic table we know that this is our s block correct yes here this is s block just a second guys I'm so sorry the second this is s block right and this is p block foreign right here in between the S block and the P block is where you will find the D Block elements these d block elements they are present from group three okay this is group three two group 12 okay from group 3 to group 12 is where you will find the D Block elements and the periodic table yes now coming to the question where is this F block situated the F block is right here at the bottom of the periodic table you will find the F block okay why is the F block already outside the periodic table that's because we did not want to disturb the disturb how beautiful the table looks just kidding actually see Xenon and radon right Xenon and radon do you see these two are the noble gases right and you are supposed to keep them here in group 18. now if we tried to fit all the F block elements right here we would have Disturbed this group and we did not want to do that because here a similarity is like a spot on right there you can see it isn't it we did not want to mess that and that is why we kept them right here they are outside the periodic table already okay now going back to the d block again so I'd have told you that d block is between the S block and the P block the D Block starts from group 3 to group 12 and as you can see there are four long series of d block there are four long series of d block okay 3D 4D 5D at 60. all right these are your D Block elements now the D Block elements they are also sometimes with love called as transition elements from where is this name coming who kept this name couldn't we just keep our life simple and just call them d block why do we have another name for them well that's because originally it was found that the property of the D Block was transitional between s block and P block okay like when you're going from s block to P block you will see that yes their properties are transitional between s block and d block so that is why we started calling them transitional image however later on iopac came up with the definition the transition elements are those which have half filled D orbitals which have half filled D orbitals in their neutral atom or in their common oxidation state and that is why even though Scandium too copper yes even though or group three to group 12 all are included in the D Block however my dear student zinc cadmium Mercury these are not considered to be transition element you're going to study their properties with the D Block elements understood till now yes what are the things that I have told you till now I have told you that the D Block elements are present between s block and t-block they are also called as transition elements originally they were called as transition elements because the properties were found to be transitional between s block and P block but later on IUPAC came up and they said that no transition elements are those which have half filled D orbitals in their neutral atom or even when they are in their common oxidation state okay now when we read about the general electronic configuration you will actually understand that why zinc cadmium and Mercury are not considered as transition elements we will understand although we read their properties I mean since they're there we have to read it okay we have to study it there is no point moving away from them so we have to study about that okay but they are included in the D Block and we will be studying their property as well okay and I had also told you that there are four long series of d block elements what are those 3D 45d and 60. clear all right these are all the things that I've told you I have also told you the position of the F block and why they are outside the periodic table already right because we did not want to mess up with the noble gases which are coming right after them we did not want to mess their position and that's why we just kept them outside they just kept them away from the periodic table right now coming to the four long series take a look at it my dear student this is 3D Scandia to zinc 4D y 2cd cadmium right FD lengthenum to Mercury and C 6D is AC to CN copernicia acting actinoids yes these actinoids yes from here to Copper Nation all right they are there now a very interesting point take a look at it do you see that one two three four actually the 3D series they belong to the fourth period then why do we call them 3D series do you notice this interesting right they belong to the fourth period but we still like to call them as 3D series that's because the electrons go into the 3D orbitals mightier students so that's why now coming to this yes although these belong to the fifth period we still call them 4D series why because the electrons go into the 40 orbitals right so that's what it is okay now I don't know if you can remember all of these or not at least make sure the least that you can do for this chapter is to remember the 3D series the 3D series is very important it's going to be very helpful for you even when you are learning for coordination compounds or other things anything and everything that you are learning the 3D series are very important so please learn the 3D series how will you remember it let me tell you a mnemonic also okay Sachin Tendulkar very crazy man free coaching NYX cousin what did I say Sachin Tendulkar very crazy man free coaching Nick's cousin and that is your Scandium titanium Vanadium chromium manganese iron copper nickel and zinc okay nickel copper zinc okay sorry Cobalt nickel copper zinc okay let me write it down somewhere let me write it down here Sachin foreign crazy man free coaching Nyx Nyx cousin we're not going to write ceu or c-o-u-s-i-n but we will just write Sachin Tendulkar very crazy man free coaching next cousin okay that's how we are going to remember it all right yes now their electronic configuration the D Block what is the general electronic configuration that they have the general electronic configuration that they have is my dear student n minus 1 d 1 to 10 that means in D orbitals you can fill one electron to 10 electron however if it is 10 electron if it is fully filled then it is not a transition element reminding you again don't forget it okay so it's n minus 1 d 1 to 10 and N is one to two Okay NS one two two all right understood everybody is this clear is this clear everybody got it clear okay moving on then now so the transition elements now as you can see this elements they have to have in completely filled D orbitals in completely filled the orbitals let me show you some example okay Scandium has uh atomic number 21. 21 atomic number is 21. so for atomic number 21 okay let me write it down atomic number 21 Scandium has atomic number 21. what is going to be the electronic configuration the electronic configuration will definitely be 1s2 2s2 2p6 3s2 3p6 can you see then I will have 4 S2 and 3 D 1. make sense take a look at it 2 plus 2 4 plus 6 10 plus 2 12 then 10 again here so 20 and 120 y okay now exactly the same way you can write it for all of them see titanium see Scandium is 21 titanium is 22 23 24 25 26 27 28 29 30. that's how you can remember it okay Scandia 21 titanium 22 Vanadium 23 chromium 24 like that you can remember for all of them okay now if I have to show you something very important for example zinc yes zinc what did I say the atomic number for Zinc is 30 right 30 okay oops what happened now for 30 what will I write it'll be 1 as 2. 2 S2 2p6 3s2 3p6 4s2 and 3D 10 do you see now even in its common oxidation state if I have to bring it to bring bring this one to its common oxidation state which can be let's say zinc plus two it can be zinc plus two right what if it tries to give away two electrons the two electrons don't you think that it will go away from 4 S to it will go from here right so even if two electrons goes away it will still have fully filled the orbital that is 3D time and that is why we cannot consider it to be a transition element which is the same scenario for zinc cadmium and Mercury all the three of them have this same case do we understand is it absolutely clear that why they are not considered in transition element because this is a question that can come in your board exams they might ask you this okay they might ask you this okay so do we understand this this is the whole scenario of transition element they are supposed to have incompletely filled D orbitals half-filled D orbital but never fully filled the orbitals that is just not possible if they have fully filled the orbitals then they are not considered to be transition elements at all okay do we understand this yes take a look at it see zinc cadmium and Mercury 3D 10 40 10 5 d10 they are not regarded as transition elements okay now what is the outer electronic configuration of the trail of the transition element this is a table that you can find it in your ncrt book also and I have picked it from ncrt book only I'm not very sure if you can see it however right here you can see see Scandium 21 titanium 22 Vanadium 23 chromium 24 this is exactly what I told you now it is clearly given in 4S how many electrons are there in 3D how many electrons are there and exactly like this you will see in 5s how many electrons are there and in 4D how many electrons are there in case of Atrium two cadmium okay that means for the 4D series what are the outermost electrons yes outermost electronic configuration is written in this table and same like that you have it for the third series as well as for the fourth series if you want you can learn it from there okay otherwise I don't know if you remember during RJ preparation I had told you that there is so magic number magic number do you remember 2 8 8 18 32 288 18 32 yeah two eight eight eighteen eighteen thirty two two eight eight eighteen eighteen thirty two basically from the let me show you from here see two you just have to add two okay so from one plus two you will find the atomic number of lithium then what you do is after adding two for three you add eight here you will find the atomic number of sodium then again you're going to eat add eight here you will find the atomic number of potassium then what you're going to do is you're going to add 18 here you will find the atomic number of Rubidium then what you're going to do is again you are going to add 18 here you will again get the atomic number of cesium and finally you are going to add 32 here to get the atomic number of francium and same thing you can do for the whole periodic table you will be able to find you will be able to find the atomic number for each and every element without actually knowing it but you can always calculate it you can always calculate it so this is called as a magic number 288 18 18 32 okay all right kind of confused find out I'm very weak in mathematics but anyway 37 55 I I I'll take a whole day I'll take the whole day if I have to calculate this much but I'm guessing you all can do it okay just figure it out if it is 2 8 8 18 18 32 or if it is 2 8 8 18 32. I'm guessing I've written it right but just just calculate the mathematical part you ask me this I think I I think I should sit in shimansa's class again and learn from him but anyway all right moving on now moving on so we understood the general electronic configuration and we have also understood what are the outer electronic configuration for all the transition element which is present in your ncrt book as well okay all right we have understood all of these now coming to the general properties of the transition element now you will find that most of these transition elements they have a metallic nature right they have they also form metallic bonds right they are naturally very hard they have high tensile strength what is tensile strength that's a question that you might ask me that Mom what is tensile strength tensile strength basically is uh the the property of an element in which I apply some tension and does it break does it break if it does not break that means it has heightensile strength but if it breaks I apply some tension and if it breaks that means it has low tensile strength okay but if I apply tension and if it does not break that means that it has heightened size strength so most of these transition elements they have high tensile strength okay they have high tensile strength and also there are some other properties that you have learned about it in your in your lower grades as well ductility malleability high melting point in boiling point right all of these you have learned but anyway let's talk about inductility what is ductility ductility is a property of the metal in which you can twist them and make them into a wire right you can twist them and pull them and you can make them into a wire what is malleability malleability is not property in which you can take a hammer and beat the metal and beat them apart and beat them again and again again and again what will you get you will get a thin sheet of the better and that's your malleability now what we have found we have found that they are Electro positive in nature what does electropositivity mean what does this electropositive mean that means I can give away their electrons that means they can give away their electrons malleability and ductility I have just told you that malleability means the property of forming sheets and ductility is the property of forming wires right electropositive you will mostly find them in the plus oxidation state as in they can give away their electrons and they have the tendency to become they have the tendency to have that positive charge so Electro positive okay generally of course there are metals most of them are metals so obviously good conductors of heat and electricity right yes they do react with oxygen at high temperature and the form oxides haven't you seen it copper oxide iron oxide yeah gold oxide gold oxide is a little hard to find but anyway all the other ones you can find oxides right yes manganese oxide mn2o see and they have different Natures also see mno is basic in nature but mn2o3 is emphatidic in nature that we will learn about and in the in the upcoming and the following classes okay right now let's focus on melting point okay so they have really high melting point do you know why and it is also seen that the melting point it increases increases increases and then it again reduces once again it increases increases increases and then it reduces why does it increase why does it increase it increases with the with the number of unpaired electron and then it reduces again now there are if there are more number of unpaired electron that means that the unpaired electrons will try to mingle with the surrounding atoms so the metallic bonding will be stronger are you understanding tell me something tell me something I'll give you an analogy everybody imagine there is a residential complex okay there is a residential complex where there are only families only families and then there is a complex where only bachelor boys are staying like hostel like your IIT hostel don't you think that in the IIT hostel the the boy is hostile oh my God the strength of the Friendship is unbreakable you can't break that friendship they will bunk they will not go to classes they will have fun together and yet you cannot break them if the professor asks that whose idea was it to Bunk the class they will be like who knows they're not gonna tell but if it is residential complex you will find that everybody is quite quite quite quite quite in their own houses they're not like partying all the time they're not like mingling all the time they're not going out all the time even if they're going it's a family family thing right you know the four people family they will go out together it's not like always they're having fun and always they're having a party do you know why because family they're already bonded they're already bonded they don't have they don't have the you know the the Affinity towards making more bonds they don't want to do that but imagine boys hostel everybody is what single single single single everyone is staying in this people get bored so they obviously would like to okay uh the Next Room who is there let me go and talk to them the Next Room who is there let me go and have fun with them the Next Room who is there let me go and ask them also if they want to Bunk the classes right so the strong the bonding is very strong the same thing happens here unpaired electrons they're all single single single in their orbitals so they all want to like you know make stronger bonding with their surrounding atoms which is why they have a very high melting point which is why they have a very high melting point and then again when the number of unpaired electrons starts decreasing what happens the melting point also drops down the melting point also drops down as you can see see copper has very low gold has very low silver has very low but here if you see tungsten has highest see understanding is this clear easy right easy okay all right moving on from here then this this this this whole thing right it's also related to something called as enthalpy of atomization what is this term enthalpy of atomization how what do we understand from this term okay enthalpy of atomization I know it looks like whoa what a big you know term what is it we can't understand but actually it's very very very easy enthalpy of atomization is basically the amount of energy required to change the atom into its gas state got it enthalpy of atomization in a very easy layman's term if I have to tell you basically the amount of energy required by the atom to change into its gas State doesn't help you of atomization nothing else easy right yes so what happens here is let me read the slide from here okay I'm going to read it understand this enthalpy of atomization of transition element it increases as the unpaired electron increases once again the same reason actually the metallic bonding is related by is is related by enthalpy of atomization okay all right it increases as the unpaired electrons increases why do you understand metallic bonding is stronger right metallic bonding is stronger that is why it increases okay all right because with the increase in unpaired electrons the inter Atomic in interactions increases listen to this the inter Atomic where is this belt let me let me let me let me with yellow I'm marking C the inter Atomic the inter Atomic interactions also increases this line this line is what I was trying to explain the inter-atomic interactions also increases and that is why what happens the metallic bonding also increases and that is why the melting point also increases understood clear yes amazing all right easy peasy Biryani is tasty right we can say that awesome okay now uh we also see that the 5D series have more enthalpy of atomization the 5D series have more enthalpy of atomization you know why we'll come to that in some time we will come to that in some time okay we'll come to that in some time anyway now let's come to the atomic radius what happens to the atomic Radiance does it increase does it decrease does it remain the same what happens to it well actually we see that the atomic radius as you go from left to right the Radia kind of decreases it becomes smaller smaller smaller smaller smaller and not so much like I'm telling you smaller smaller smaller I it you will find that from Scandium to manganese okay let me get the red again from Scandium to manganese you will see that there is a constant drop in the atomic radius then again from here to here from Iron to Copper you will see that it almost remains constant okay you will see that it almost remains constant do you know why do you know why because now here we have to understand a term which we have obviously understood in the earlier uh you know in the earlier blocks that we have studied like as block and P block and all of these but right here once again I have to tell you there is something called as shielding effect there is something called as shielding effect okay so my idea students can you all see me clearly right now you all can see me clearly absolutely clearly right now what if I take a book I have a book here I have a book here right what if I take a book and keep it like this am I not shielding myself from the camera I am I shielded myself you could not see me right you could not see me Shield the word Shield everybody understand right there is a sword and there is a shield what do you do you protect yourself you protect yourself with the shield when the other person is drawing the sword what can you do is you Shield yourself right yes correct the shading work is also done by our curtains in our houses yes why do we why do we you know put the curtains in our houses because we do not want our neighbors to see what we are doing in the house I might be dancing but I don't want my neighbors to see and that is what I'm doing I'm shielding myself the same way what happens is let me draw an atom here where can I draw let me draw an atom here let's say that this is my atom okay this is the nucleus of the atom now do you understand that there are electrons here there are electrons here and there are electrons here as well right now let me change the color now the electron that is here the electron that is here the electron that is here okay they are they are not absolutely visible by the nucleus the nucleus is here this is our nucleus the nucleus is not able to see these electrons because there are electrons here there are electrons here there are electrons here there are electrons here yes so in the inner orbitals the electrons that are there they are shielding the outer electrons they are not allowing the outer electrons to be visible to the nucleus understanding yes all right now I'm gonna tell you the same thing once again you know about eclipses solar eclipse lunar eclipse right solar eclipse lunar eclipse what happens when there is a solar eclipse the moon comes in between the moon Shields the sun right and suddenly we form we all feel like whoa it's evening the birds and all they fly they're like you know it's evening it's evening let's go go to the house they go to the nests right why because the sun was shielded by the moon you couldn't see the sun why because the moon came in between the same thing happens here the electrons that are present in the inner orbitals they do not allow the outer electrons to be visible for the nucleus which is why the nucleus which has positive charges it is not able to pull the electrons and those electrons they think like we are free birds so they all fly away and they go they consider themselves to be free Free Birds because the nucleus is not able to pull them one more analogy my dear student when you don't have a teacher in your class what are you all doing make everybody shouts and it's like a fish market then your class teacher comes in like yeah is this a fish market then you're like at that time you are shielded the moment your teacher steps out again you all startling right yeah why because you consider yourself Freebird you think that now the teacher is not there to control us so why should we stay here we are going to go uncontrollable we are going to do whatever we can right exactly the same thing the electrons when they're not when they are not in the you know when when the nuclear charges are not enough they think that we are free but they're like and they want to fly away right but in here what happens now understand this so every orbit every orbital they have their own kind of shielding effect now s block is round in shape and because it is round in shape the shielding effect is strong the all over the shielding effect is there so the outer electron is absolutely shielded the nucleus cannot see the outer electron at all so the outer electron is absolutely free and it just tries to run away right now T block is a dumbbell shaped right the P block kind of looks like this this is how the P block orbital looks now if an electron is here then obviously the nucleus can see this electron and it can bring it close correct it can bring it closely absolutely right now the D Block the D Block looks like this so that means if an electron is here if an electron is here if an electron is here or if the electron is here there are four more spaces created from where the electron can be visible four more spaces that are created from where the electron can be visible for the nucleus so the D orbitals they have a poor shielding effect yes the inner orbital the electrons present in the inner orbital they cannot Shield the outer orbital they they cannot Shield the outer electron and the outer electrons are pulled by the nucleus F orbitals they have even poor shielding so they cannot I mean they they hardly Shield anything basically like everything is right there imagine having a house made up of glass where is the shielding you will have to put so much of curtains that it's it's just an extra extra wastage of money right rather you could have built a house with walls and everything right right everybody yeah so understanding now yeah so the F orbitals are basically like the glass walls like everything is visible everything is visible okay so the F orbitals are the least or the poorest shielders the D orbitals are a little better but they are also very poor P orbitals are again a little bit better but the S ones are the best shielders okay all right now because of this poor shielding effect of D orbitals what happens the outermost electrons is clearly almost clearly visible by the nucleus and they pull them okay the nucleus pulls the electron and that is why the size decreases that is why the size decreases understanding yeah that is why the size decreases okay now if you notice I'm going to rub this okay if I just told it I'm going to rub the this thing these are just going to disturb you when you're reading correct okay now now as you can see that in atomic radius yes atomic radius in case of 4D and 5T it's almost similar can you guess why I just told you lanthanoid contraction who are the lanthanoids the F block ones the F block ones that means F orbital is introduced if F orbital is introduced then you know that they have the very poorest quality of shielding if they have very poor quality of shielding then obviously the electrons which are at right at the end can be easily visible to the nucleus and the nucleus we pull it like Spiderman you know it'll pull it okay it will pull it and that's why the size will reduce okay that's why the size will do so you will see that the atomic radius in case of 4D and 5T they're almost same same the radius of the elements are almost same same because of lanthanoid contraction is this clear is this clear you see that zirconium has only 160 picometer and half Neo has only 159 picometer although we would want it to increase right in case of zirconium and half we would want it to we would want it to increase because hey 4D and then 5D there are electrons that are present in the next Shell not in 40 no not in 4S it's in 5D so ideally we would want the size to increase but no because of the four F electrons being present now the size contracts it decreases okay and that is called as lanthanoid contraction cool everybody lanthanoid contraction is probably one of the most repeated question that that is asked in the board so just read it once okay from ncrt anyway I'll give you the notes also so don't worry about it don't worry about it sure now we under we try to understand the ionization energy what is ionization energy ionization energy my dear student is the amount of energy given to an atom to take its electron away let's understand this with an analogy let's understand this with an analogy so you you know what being being a female right I'm a female I'm a girl I'm a lady and um I love shopping I can't help it I really do love shopping now I usually shop from myntra and uh what do you have as you and all of those online sites right so I I even even now I have my card ready on myntra and I don't want to shop but you know I have kind of promised myself that hey navamita you're not going to shop so much so I'm just you know trying to trying very hard to control myself to not shop however the cart is ready now I really like let's say a pair of jeans right I really love this pair of jeans and I really want to buy it but the moment I hit add to card and I and I hit uh order what happens I lose some amount of money from my account yeah don't I I do right yeah the moment I hit on order what do I do I'm going to lose some money from my account so basically to get something to get that pair of jeans what am I doing I'm losing some amount of money right the same thing happens here as well try to understand this so if there is another term there are electrons in different different shells now the outermost electrons are the ones that are available for you to take them away correct for you to take them away example in your school you are in the class do you think if you are in the class your class class teacher is teaching you suddenly your principal will come and tell you that Rahul come I have a complaint against you no but imagine if you're roaming in the corridor like this then definitely your principal will come and you're like come here what are you doing during the class ask why are you roaming around in the corridor right because you are a free bird you're roaming in the corridor obviously your principal will come and take you along right same thing so the electrons that are outside they are available for you to take them away and why and how will you take them away you're going to give them some energy you are you will have to give the atom some energy to take it away that's called a zionization energy now the ionization energy does not increase so much here you see that it does not increase so much here but suddenly it increases yes suddenly it increases okay it increases suddenly okay you can see it here also in case of iridium it increases in case of iron it increases in case of Palladium it increases do you know why Palladium is an exception by the way Palladium is an exception everywhere it is bought everywhere they have a n minus 1 d 1 to 10 n is one to two configuration right but Palladio my dear student only has 5S 0 4 d10 the electronic configuration of Palladium let me write it down Palladium electronic configuration is 5 S 0 4 d ten this is an exception this is an exception okay write it down this is an exception 4-10 now why is it that the ionization energy increases the ionization energy increases because of lanthanoid contraction the poor shielding effect of D and F orbitals they bring the size of the atom they bring the size of the atom you know less right they bring it down basically they bring down the size of the atom and when the size of the atom decreases you understand that already the protons are able to see the electrons so they will they will bring it close they will bring the electrons closer and that is why now the protons are trying to bring the electrons close if you are trying to take the electron away you have to put in more energy now you'll have to put in more energy right yes only when you put in more energy then only the proton will be like the or the nucleus will be like okay you're giving me too much energy take it away take it away right understanding everybody understanding guys yes so this is what it is okay this is what it is about ionization energy all right we understand now right here I only spoke to you about the first ionization energy the first ionization energy can be a little less however the second and the third ionization energy usually increases it usually increases generally I said usually generally but not always not always there are certain cases when let's say that let's say that uh you know there is an element with 3d6 3d6 it can give away one electron very easily it can give away one electron very easily but after that when it is I think three D5 it is half filled and if it is half filled the half filled and the fully filled orbitals they have major stability they don't want to take they don't want to give away their stability so the second ionization energy will be higher the second ionization energy will be higher because they don't want to mess up with the stability understanding they don't want to mess up with the stability got it clear okay so this is what happened here okay this is the story of ionization enthalpy or ionization energy now let's come to the last point of today's session that is oxidation state remember in the beginning I told you that transition elements are those Elements which have half filled or fully they have half filled or partially filled D orbitals in their neutral atom or most common oxidation state just look at the table can you tell me what is the most common oxidation state we can plus 2 plus 2 plus 2 plus 2 plus 2 plus 2 plus 2 plus 2 plus 2. plus 2 is the most common oxidation state and if I talk about zinc even zinc in its plus two oxidation state what will it be 4 is to 3D 10 it will give away the electrons from forest to 3D 10 still fully filled even in its most common oxidation state it still cannot have partially filled D orbitals and that's why it's not called as transition element but in here you see that when you come to the middle of the series middle of the 3D series or the 4D series or the 5D series you will always find that they have variable oxidation state they show major major they show more number of variable oxidation state although all of them are showing all of them are showing Scandium and zinc they do not show you variable oxidation state Scandium can only show you plus three and zinc can only show you plus two did I say Scandium is think I hope so yeah so Scandium can only show plus three oxidation state and zinc can only show plus two oxidation state now coming to the question do you have this in mind why Scandium cannot show plus one or plus two y plus three because what is the electronic configuration 4 is to 3D one if it gives away one then it will be four S one three D one now four S and 3D they both have very close energy the energy gap is very you know very close the energy gap is not too high it's very close so what happens is the 4S electrons they're like hey we are the ones who are outside but the 3D was like so what I'm also right behind you only imagine in a class there are two Toppers right like sometimes let's say there are two students RAM and shyam in one test Ram gets 99.9 and charm got 99.8 the next one only Sean got 99.9 Ram got 99.8 so these two are constantly fighting fighting fighting fighting fighting and you can never understand which one is the topper which one is exactly the topper because in one exam the ram is a Topper in my other exam is the topic so every time Ram gets more mass Ram is like hey see I'm the topper charm is like so what bro next exam I'll show you this is exactly the case for them also the forest ones are like hey we are the ones who are the Ultimate Energy shells you know the 3D ones are like we're just right next to you don't worry about it we are right here yeah so the energy gap is so low the energy gap between them is so low that the moment Scandium loses one the other two would it is easier for them to lose the other two and then attain stability plus three is more viable option for them okay plus three is more viable option for them same for zinc the moment zinc loses plus zinc loses two electrons it is three D ten and then it's like try giving me more energy I'm not gonna give away the electron only so plus 2 is a more viable option okay all right but otherwise you get to see a lot of variable oxidation state why do you say variable oxidation say once again the similar energies of NS and N minus 1 see the 4S and 3D orbitals they have such close energy gaps that you know the moment you take away one electron the 3D is like I also have electrons why can't you take it from me also and that results in variable oxidation state do we understand this do we understand this okay that results in the variable oxidation state now in the upcoming classes we will be learning about standard electrode potential we will be learning about other properties that are there yes uh so please stay tuned to this channel if you are a regular in this channel then amazing don't forget to like this video but if you are new to this channel don't forget to share and subscribe with your friends because the more students you share with more students get benefited and of course don't forget to like the video yeah I have put in a lot of efforts to take this session and will be amazing if you like the video it'll give me a little bit of happiness a lot of happiness in that so with this note everybody I'll see you soon with the next session and all the very best for your board exam start preparing right now bye

thank you hi everybody very very very warm welcome to vedanta J English Channel this is your master teacher and today we are here to discuss the dnf block chapter okay not the whole chapter of course because we are preparing for our board exams and uh this chapter and coordination compounds are the chapters from inorganic chemistry that are there in your syllabus so in today&#39;s session we are going to talk about the general electronic configuration we&#39;re going to talk about some of the general properties and we are going to talk about the position of the dnf block and why they are kept there and some other terms and you know conditions that are applied to these block basically okay all right so let&#39;s start without much further Ado because we know that our exams are coming oh once again at the door right so let&#39;s begin everybody so the first thing that comes in our mind is where exactly are this dnf block placed in the periodic table now the moment we look at the periodic table we know that this is our s block correct yes here this is s block just a second guys I&#39;m so sorry the second this is s block right and this is p block foreign right here in between the S block and the P block is where you will find the D Block elements these d block elements they are present from group three okay this is group three two group 12 okay from group 3 to group 12 is where you will find the D Block elements and the periodic table yes now coming to the question where is this F block situated the F block is right here at the bottom of the periodic table you will find the F block okay why is the F block already outside the periodic table that&#39;s because we did not want to disturb the disturb how beautiful the table looks just kidding actually see Xenon and radon right Xenon and radon do you see these two are the noble gases right and you are supposed to keep them here in group 18. now if we tried to fit all the F block elements right here we would have Disturbed this group and we did not want to do that because here a similarity is like a spot on right there you can see it isn&#39;t it we did not want to mess that and that is why we kept them right here they are outside the periodic table already okay now going back to the d block again so I&#39;d have told you that d block is between the S block and the P block the D Block starts from group 3 to group 12 and as you can see there are four long series of d block there are four long series of d block okay 3D 4D 5D at 60. all right these are your D Block elements now the D Block elements they are also sometimes with love called as transition elements from where is this name coming who kept this name couldn&#39;t we just keep our life simple and just call them d block why do we have another name for them well that&#39;s because originally it was found that the property of the D Block was transitional between s block and P block okay like when you&#39;re going from s block to P block you will see that yes their properties are transitional between s block and d block so that is why we started calling them transitional image however later on iopac came up with the definition the transition elements are those which have half filled D orbitals which have half filled D orbitals in their neutral atom or in their common oxidation state and that is why even though Scandium too copper yes even though or group three to group 12 all are included in the D Block however my dear student zinc cadmium Mercury these are not considered to be transition element you&#39;re going to study their properties with the D Block elements understood till now yes what are the things that I have told you till now I have told you that the D Block elements are present between s block and t-block they are also called as transition elements originally they were called as transition elements because the properties were found to be transitional between s block and P block but later on IUPAC came up and they said that no transition elements are those which have half filled D orbitals in their neutral atom or even when they are in their common oxidation state okay now when we read about the general electronic configuration you will actually understand that why zinc cadmium and Mercury are not considered as transition elements we will understand although we read their properties I mean since they&#39;re there we have to read it okay we have to study it there is no point moving away from them so we have to study about that okay but they are included in the D Block and we will be studying their property as well okay and I had also told you that there are four long series of d block elements what are those 3D 45d and 60. clear all right these are all the things that I&#39;ve told you I have also told you the position of the F block and why they are outside the periodic table already right because we did not want to mess up with the noble gases which are coming right after them we did not want to mess their position and that&#39;s why we just kept them outside they just kept them away from the periodic table right now coming to the four long series take a look at it my dear student this is 3D Scandia to zinc 4D y 2cd cadmium right FD lengthenum to Mercury and C 6D is AC to CN copernicia acting actinoids yes these actinoids yes from here to Copper Nation all right they are there now a very interesting point take a look at it do you see that one two three four actually the 3D series they belong to the fourth period then why do we call them 3D series do you notice this interesting right they belong to the fourth period but we still like to call them as 3D series that&#39;s because the electrons go into the 3D orbitals mightier students so that&#39;s why now coming to this yes although these belong to the fifth period we still call them 4D series why because the electrons go into the 40 orbitals right so that&#39;s what it is okay now I don&#39;t know if you can remember all of these or not at least make sure the least that you can do for this chapter is to remember the 3D series the 3D series is very important it&#39;s going to be very helpful for you even when you are learning for coordination compounds or other things anything and everything that you are learning the 3D series are very important so please learn the 3D series how will you remember it let me tell you a mnemonic also okay Sachin Tendulkar very crazy man free coaching NYX cousin what did I say Sachin Tendulkar very crazy man free coaching Nick&#39;s cousin and that is your Scandium titanium Vanadium chromium manganese iron copper nickel and zinc okay nickel copper zinc okay sorry Cobalt nickel copper zinc okay let me write it down somewhere let me write it down here Sachin foreign crazy man free coaching Nyx Nyx cousin we&#39;re not going to write ceu or c-o-u-s-i-n but we will just write Sachin Tendulkar very crazy man free coaching next cousin okay that&#39;s how we are going to remember it all right yes now their electronic configuration the D Block what is the general electronic configuration that they have the general electronic configuration that they have is my dear student n minus 1 d 1 to 10 that means in D orbitals you can fill one electron to 10 electron however if it is 10 electron if it is fully filled then it is not a transition element reminding you again don&#39;t forget it okay so it&#39;s n minus 1 d 1 to 10 and N is one to two Okay NS one two two all right understood everybody is this clear is this clear everybody got it clear okay moving on then now so the transition elements now as you can see this elements they have to have in completely filled D orbitals in completely filled the orbitals let me show you some example okay Scandium has uh atomic number 21. 21 atomic number is 21. so for atomic number 21 okay let me write it down atomic number 21 Scandium has atomic number 21. what is going to be the electronic configuration the electronic configuration will definitely be 1s2 2s2 2p6 3s2 3p6 can you see then I will have 4 S2 and 3 D 1. make sense take a look at it 2 plus 2 4 plus 6 10 plus 2 12 then 10 again here so 20 and 120 y okay now exactly the same way you can write it for all of them see titanium see Scandium is 21 titanium is 22 23 24 25 26 27 28 29 30. that&#39;s how you can remember it okay Scandia 21 titanium 22 Vanadium 23 chromium 24 like that you can remember for all of them okay now if I have to show you something very important for example zinc yes zinc what did I say the atomic number for Zinc is 30 right 30 okay oops what happened now for 30 what will I write it&#39;ll be 1 as 2. 2 S2 2p6 3s2 3p6 4s2 and 3D 10 do you see now even in its common oxidation state if I have to bring it to bring bring this one to its common oxidation state which can be let&#39;s say zinc plus two it can be zinc plus two right what if it tries to give away two electrons the two electrons don&#39;t you think that it will go away from 4 S to it will go from here right so even if two electrons goes away it will still have fully filled the orbital that is 3D time and that is why we cannot consider it to be a transition element which is the same scenario for zinc cadmium and Mercury all the three of them have this same case do we understand is it absolutely clear that why they are not considered in transition element because this is a question that can come in your board exams they might ask you this okay they might ask you this okay so do we understand this this is the whole scenario of transition element they are supposed to have incompletely filled D orbitals half-filled D orbital but never fully filled the orbitals that is just not possible if they have fully filled the orbitals then they are not considered to be transition elements at all okay do we understand this yes take a look at it see zinc cadmium and Mercury 3D 10 40 10 5 d10 they are not regarded as transition elements okay now what is the outer electronic configuration of the trail of the transition element this is a table that you can find it in your ncrt book also and I have picked it from ncrt book only I&#39;m not very sure if you can see it however right here you can see see Scandium 21 titanium 22 Vanadium 23 chromium 24 this is exactly what I told you now it is clearly given in 4S how many electrons are there in 3D how many electrons are there and exactly like this you will see in 5s how many electrons are there and in 4D how many electrons are there in case of Atrium two cadmium okay that means for the 4D series what are the outermost electrons yes outermost electronic configuration is written in this table and same like that you have it for the third series as well as for the fourth series if you want you can learn it from there okay otherwise I don&#39;t know if you remember during RJ preparation I had told you that there is so magic number magic number do you remember 2 8 8 18 32 288 18 32 yeah two eight eight eighteen eighteen thirty two two eight eight eighteen eighteen thirty two basically from the let me show you from here see two you just have to add two okay so from one plus two you will find the atomic number of lithium then what you do is after adding two for three you add eight here you will find the atomic number of sodium then again you&#39;re going to eat add eight here you will find the atomic number of potassium then what you&#39;re going to do is you&#39;re going to add 18 here you will find the atomic number of Rubidium then what you&#39;re going to do is again you are going to add 18 here you will again get the atomic number of cesium and finally you are going to add 32 here to get the atomic number of francium and same thing you can do for the whole periodic table you will be able to find you will be able to find the atomic number for each and every element without actually knowing it but you can always calculate it you can always calculate it so this is called as a magic number 288 18 18 32 okay all right kind of confused find out I&#39;m very weak in mathematics but anyway 37 55 I I I&#39;ll take a whole day I&#39;ll take the whole day if I have to calculate this much but I&#39;m guessing you all can do it okay just figure it out if it is 2 8 8 18 18 32 or if it is 2 8 8 18 32. I&#39;m guessing I&#39;ve written it right but just just calculate the mathematical part you ask me this I think I I think I should sit in shimansa&#39;s class again and learn from him but anyway all right moving on now moving on so we understood the general electronic configuration and we have also understood what are the outer electronic configuration for all the transition element which is present in your ncrt book as well okay all right we have understood all of these now coming to the general properties of the transition element now you will find that most of these transition elements they have a metallic nature right they have they also form metallic bonds right they are naturally very hard they have high tensile strength what is tensile strength that&#39;s a question that you might ask me that Mom what is tensile strength tensile strength basically is uh the the property of an element in which I apply some tension and does it break does it break if it does not break that means it has heightensile strength but if it breaks I apply some tension and if it breaks that means it has low tensile strength okay but if I apply tension and if it does not break that means that it has heightened size strength so most of these transition elements they have high tensile strength okay they have high tensile strength and also there are some other properties that you have learned about it in your in your lower grades as well ductility malleability high melting point in boiling point right all of these you have learned but anyway let&#39;s talk about inductility what is ductility ductility is a property of the metal in which you can twist them and make them into a wire right you can twist them and pull them and you can make them into a wire what is malleability malleability is not property in which you can take a hammer and beat the metal and beat them apart and beat them again and again again and again what will you get you will get a thin sheet of the better and that&#39;s your malleability now what we have found we have found that they are Electro positive in nature what does electropositivity mean what does this electropositive mean that means I can give away their electrons that means they can give away their electrons malleability and ductility I have just told you that malleability means the property of forming sheets and ductility is the property of forming wires right electropositive you will mostly find them in the plus oxidation state as in they can give away their electrons and they have the tendency to become they have the tendency to have that positive charge so Electro positive okay generally of course there are metals most of them are metals so obviously good conductors of heat and electricity right yes they do react with oxygen at high temperature and the form oxides haven&#39;t you seen it copper oxide iron oxide yeah gold oxide gold oxide is a little hard to find but anyway all the other ones you can find oxides right yes manganese oxide mn2o see and they have different Natures also see mno is basic in nature but mn2o3 is emphatidic in nature that we will learn about and in the in the upcoming and the following classes okay right now let&#39;s focus on melting point okay so they have really high melting point do you know why and it is also seen that the melting point it increases increases increases and then it again reduces once again it increases increases increases and then it reduces why does it increase why does it increase it increases with the with the number of unpaired electron and then it reduces again now there are if there are more number of unpaired electron that means that the unpaired electrons will try to mingle with the surrounding atoms so the metallic bonding will be stronger are you understanding tell me something tell me something I&#39;ll give you an analogy everybody imagine there is a residential complex okay there is a residential complex where there are only families only families and then there is a complex where only bachelor boys are staying like hostel like your IIT hostel don&#39;t you think that in the IIT hostel the the boy is hostile oh my God the strength of the Friendship is unbreakable you can&#39;t break that friendship they will bunk they will not go to classes they will have fun together and yet you cannot break them if the professor asks that whose idea was it to Bunk the class they will be like who knows they&#39;re not gonna tell but if it is residential complex you will find that everybody is quite quite quite quite quite in their own houses they&#39;re not like partying all the time they&#39;re not like mingling all the time they&#39;re not going out all the time even if they&#39;re going it&#39;s a family family thing right you know the four people family they will go out together it&#39;s not like always they&#39;re having fun and always they&#39;re having a party do you know why because family they&#39;re already bonded they&#39;re already bonded they don&#39;t have they don&#39;t have the you know the the Affinity towards making more bonds they don&#39;t want to do that but imagine boys hostel everybody is what single single single single everyone is staying in this people get bored so they obviously would like to okay uh the Next Room who is there let me go and talk to them the Next Room who is there let me go and have fun with them the Next Room who is there let me go and ask them also if they want to Bunk the classes right so the strong the bonding is very strong the same thing happens here unpaired electrons they&#39;re all single single single in their orbitals so they all want to like you know make stronger bonding with their surrounding atoms which is why they have a very high melting point which is why they have a very high melting point and then again when the number of unpaired electrons starts decreasing what happens the melting point also drops down the melting point also drops down as you can see see copper has very low gold has very low silver has very low but here if you see tungsten has highest see understanding is this clear easy right easy okay all right moving on from here then this this this this whole thing right it&#39;s also related to something called as enthalpy of atomization what is this term enthalpy of atomization how what do we understand from this term okay enthalpy of atomization I know it looks like whoa what a big you know term what is it we can&#39;t understand but actually it&#39;s very very very easy enthalpy of atomization is basically the amount of energy required to change the atom into its gas state got it enthalpy of atomization in a very easy layman&#39;s term if I have to tell you basically the amount of energy required by the atom to change into its gas State doesn&#39;t help you of atomization nothing else easy right yes so what happens here is let me read the slide from here okay I&#39;m going to read it understand this enthalpy of atomization of transition element it increases as the unpaired electron increases once again the same reason actually the metallic bonding is related by is is related by enthalpy of atomization okay all right it increases as the unpaired electrons increases why do you understand metallic bonding is stronger right metallic bonding is stronger that is why it increases okay all right because with the increase in unpaired electrons the inter Atomic in interactions increases listen to this the inter Atomic where is this belt let me let me let me let me with yellow I&#39;m marking C the inter Atomic the inter Atomic interactions also increases this line this line is what I was trying to explain the inter-atomic interactions also increases and that is why what happens the metallic bonding also increases and that is why the melting point also increases understood clear yes amazing all right easy peasy Biryani is tasty right we can say that awesome okay now uh we also see that the 5D series have more enthalpy of atomization the 5D series have more enthalpy of atomization you know why we&#39;ll come to that in some time we will come to that in some time okay we&#39;ll come to that in some time anyway now let&#39;s come to the atomic radius what happens to the atomic Radiance does it increase does it decrease does it remain the same what happens to it well actually we see that the atomic radius as you go from left to right the Radia kind of decreases it becomes smaller smaller smaller smaller smaller and not so much like I&#39;m telling you smaller smaller smaller I it you will find that from Scandium to manganese okay let me get the red again from Scandium to manganese you will see that there is a constant drop in the atomic radius then again from here to here from Iron to Copper you will see that it almost remains constant okay you will see that it almost remains constant do you know why do you know why because now here we have to understand a term which we have obviously understood in the earlier uh you know in the earlier blocks that we have studied like as block and P block and all of these but right here once again I have to tell you there is something called as shielding effect there is something called as shielding effect okay so my idea students can you all see me clearly right now you all can see me clearly absolutely clearly right now what if I take a book I have a book here I have a book here right what if I take a book and keep it like this am I not shielding myself from the camera I am I shielded myself you could not see me right you could not see me Shield the word Shield everybody understand right there is a sword and there is a shield what do you do you protect yourself you protect yourself with the shield when the other person is drawing the sword what can you do is you Shield yourself right yes correct the shading work is also done by our curtains in our houses yes why do we why do we you know put the curtains in our houses because we do not want our neighbors to see what we are doing in the house I might be dancing but I don&#39;t want my neighbors to see and that is what I&#39;m doing I&#39;m shielding myself the same way what happens is let me draw an atom here where can I draw let me draw an atom here let&#39;s say that this is my atom okay this is the nucleus of the atom now do you understand that there are electrons here there are electrons here and there are electrons here as well right now let me change the color now the electron that is here the electron that is here the electron that is here okay they are they are not absolutely visible by the nucleus the nucleus is here this is our nucleus the nucleus is not able to see these electrons because there are electrons here there are electrons here there are electrons here there are electrons here yes so in the inner orbitals the electrons that are there they are shielding the outer electrons they are not allowing the outer electrons to be visible to the nucleus understanding yes all right now I&#39;m gonna tell you the same thing once again you know about eclipses solar eclipse lunar eclipse right solar eclipse lunar eclipse what happens when there is a solar eclipse the moon comes in between the moon Shields the sun right and suddenly we form we all feel like whoa it&#39;s evening the birds and all they fly they&#39;re like you know it&#39;s evening it&#39;s evening let&#39;s go go to the house they go to the nests right why because the sun was shielded by the moon you couldn&#39;t see the sun why because the moon came in between the same thing happens here the electrons that are present in the inner orbitals they do not allow the outer electrons to be visible for the nucleus which is why the nucleus which has positive charges it is not able to pull the electrons and those electrons they think like we are free birds so they all fly away and they go they consider themselves to be free Free Birds because the nucleus is not able to pull them one more analogy my dear student when you don&#39;t have a teacher in your class what are you all doing make everybody shouts and it&#39;s like a fish market then your class teacher comes in like yeah is this a fish market then you&#39;re like at that time you are shielded the moment your teacher steps out again you all startling right yeah why because you consider yourself Freebird you think that now the teacher is not there to control us so why should we stay here we are going to go uncontrollable we are going to do whatever we can right exactly the same thing the electrons when they&#39;re not when they are not in the you know when when the nuclear charges are not enough they think that we are free but they&#39;re like and they want to fly away right but in here what happens now understand this so every orbit every orbital they have their own kind of shielding effect now s block is round in shape and because it is round in shape the shielding effect is strong the all over the shielding effect is there so the outer electron is absolutely shielded the nucleus cannot see the outer electron at all so the outer electron is absolutely free and it just tries to run away right now T block is a dumbbell shaped right the P block kind of looks like this this is how the P block orbital looks now if an electron is here then obviously the nucleus can see this electron and it can bring it close correct it can bring it closely absolutely right now the D Block the D Block looks like this so that means if an electron is here if an electron is here if an electron is here or if the electron is here there are four more spaces created from where the electron can be visible four more spaces that are created from where the electron can be visible for the nucleus so the D orbitals they have a poor shielding effect yes the inner orbital the electrons present in the inner orbital they cannot Shield the outer orbital they they cannot Shield the outer electron and the outer electrons are pulled by the nucleus F orbitals they have even poor shielding so they cannot I mean they they hardly Shield anything basically like everything is right there imagine having a house made up of glass where is the shielding you will have to put so much of curtains that it&#39;s it&#39;s just an extra extra wastage of money right rather you could have built a house with walls and everything right right everybody yeah so understanding now yeah so the F orbitals are basically like the glass walls like everything is visible everything is visible okay so the F orbitals are the least or the poorest shielders the D orbitals are a little better but they are also very poor P orbitals are again a little bit better but the S ones are the best shielders okay all right now because of this poor shielding effect of D orbitals what happens the outermost electrons is clearly almost clearly visible by the nucleus and they pull them okay the nucleus pulls the electron and that is why the size decreases that is why the size decreases understanding yeah that is why the size decreases okay now if you notice I&#39;m going to rub this okay if I just told it I&#39;m going to rub the this thing these are just going to disturb you when you&#39;re reading correct okay now now as you can see that in atomic radius yes atomic radius in case of 4D and 5T it&#39;s almost similar can you guess why I just told you lanthanoid contraction who are the lanthanoids the F block ones the F block ones that means F orbital is introduced if F orbital is introduced then you know that they have the very poorest quality of shielding if they have very poor quality of shielding then obviously the electrons which are at right at the end can be easily visible to the nucleus and the nucleus we pull it like Spiderman you know it&#39;ll pull it okay it will pull it and that&#39;s why the size will reduce okay that&#39;s why the size will do so you will see that the atomic radius in case of 4D and 5T they&#39;re almost same same the radius of the elements are almost same same because of lanthanoid contraction is this clear is this clear you see that zirconium has only 160 picometer and half Neo has only 159 picometer although we would want it to increase right in case of zirconium and half we would want it to we would want it to increase because hey 4D and then 5D there are electrons that are present in the next Shell not in 40 no not in 4S it&#39;s in 5D so ideally we would want the size to increase but no because of the four F electrons being present now the size contracts it decreases okay and that is called as lanthanoid contraction cool everybody lanthanoid contraction is probably one of the most repeated question that that is asked in the board so just read it once okay from ncrt anyway I&#39;ll give you the notes also so don&#39;t worry about it don&#39;t worry about it sure now we under we try to understand the ionization energy what is ionization energy ionization energy my dear student is the amount of energy given to an atom to take its electron away let&#39;s understand this with an analogy let&#39;s understand this with an analogy so you you know what being being a female right I&#39;m a female I&#39;m a girl I&#39;m a lady and um I love shopping I can&#39;t help it I really do love shopping now I usually shop from myntra and uh what do you have as you and all of those online sites right so I I even even now I have my card ready on myntra and I don&#39;t want to shop but you know I have kind of promised myself that hey navamita you&#39;re not going to shop so much so I&#39;m just you know trying to trying very hard to control myself to not shop however the cart is ready now I really like let&#39;s say a pair of jeans right I really love this pair of jeans and I really want to buy it but the moment I hit add to card and I and I hit uh order what happens I lose some amount of money from my account yeah don&#39;t I I do right yeah the moment I hit on order what do I do I&#39;m going to lose some money from my account so basically to get something to get that pair of jeans what am I doing I&#39;m losing some amount of money right the same thing happens here as well try to understand this so if there is another term there are electrons in different different shells now the outermost electrons are the ones that are available for you to take them away correct for you to take them away example in your school you are in the class do you think if you are in the class your class class teacher is teaching you suddenly your principal will come and tell you that Rahul come I have a complaint against you no but imagine if you&#39;re roaming in the corridor like this then definitely your principal will come and you&#39;re like come here what are you doing during the class ask why are you roaming around in the corridor right because you are a free bird you&#39;re roaming in the corridor obviously your principal will come and take you along right same thing so the electrons that are outside they are available for you to take them away and why and how will you take them away you&#39;re going to give them some energy you are you will have to give the atom some energy to take it away that&#39;s called a zionization energy now the ionization energy does not increase so much here you see that it does not increase so much here but suddenly it increases yes suddenly it increases okay it increases suddenly okay you can see it here also in case of iridium it increases in case of iron it increases in case of Palladium it increases do you know why Palladium is an exception by the way Palladium is an exception everywhere it is bought everywhere they have a n minus 1 d 1 to 10 n is one to two configuration right but Palladio my dear student only has 5S 0 4 d10 the electronic configuration of Palladium let me write it down Palladium electronic configuration is 5 S 0 4 d ten this is an exception this is an exception okay write it down this is an exception 4-10 now why is it that the ionization energy increases the ionization energy increases because of lanthanoid contraction the poor shielding effect of D and F orbitals they bring the size of the atom they bring the size of the atom you know less right they bring it down basically they bring down the size of the atom and when the size of the atom decreases you understand that already the protons are able to see the electrons so they will they will bring it close they will bring the electrons closer and that is why now the protons are trying to bring the electrons close if you are trying to take the electron away you have to put in more energy now you&#39;ll have to put in more energy right yes only when you put in more energy then only the proton will be like the or the nucleus will be like okay you&#39;re giving me too much energy take it away take it away right understanding everybody understanding guys yes so this is what it is okay this is what it is about ionization energy all right we understand now right here I only spoke to you about the first ionization energy the first ionization energy can be a little less however the second and the third ionization energy usually increases it usually increases generally I said usually generally but not always not always there are certain cases when let&#39;s say that let&#39;s say that uh you know there is an element with 3d6 3d6 it can give away one electron very easily it can give away one electron very easily but after that when it is I think three D5 it is half filled and if it is half filled the half filled and the fully filled orbitals they have major stability they don&#39;t want to take they don&#39;t want to give away their stability so the second ionization energy will be higher the second ionization energy will be higher because they don&#39;t want to mess up with the stability understanding they don&#39;t want to mess up with the stability got it clear okay so this is what happened here okay this is the story of ionization enthalpy or ionization energy now let&#39;s come to the last point of today&#39;s session that is oxidation state remember in the beginning I told you that transition elements are those Elements which have half filled or fully they have half filled or partially filled D orbitals in their neutral atom or most common oxidation state just look at the table can you tell me what is the most common oxidation state we can plus 2 plus 2 plus 2 plus 2 plus 2 plus 2 plus 2 plus 2 plus 2. plus 2 is the most common oxidation state and if I talk about zinc even zinc in its plus two oxidation state what will it be 4 is to 3D 10 it will give away the electrons from forest to 3D 10 still fully filled even in its most common oxidation state it still cannot have partially filled D orbitals and that&#39;s why it&#39;s not called as transition element but in here you see that when you come to the middle of the series middle of the 3D series or the 4D series or the 5D series you will always find that they have variable oxidation state they show major major they show more number of variable oxidation state although all of them are showing all of them are showing Scandium and zinc they do not show you variable oxidation state Scandium can only show you plus three and zinc can only show you plus two did I say Scandium is think I hope so yeah so Scandium can only show plus three oxidation state and zinc can only show plus two oxidation state now coming to the question do you have this in mind why Scandium cannot show plus one or plus two y plus three because what is the electronic configuration 4 is to 3D one if it gives away one then it will be four S one three D one now four S and 3D they both have very close energy the energy gap is very you know very close the energy gap is not too high it&#39;s very close so what happens is the 4S electrons they&#39;re like hey we are the ones who are outside but the 3D was like so what I&#39;m also right behind you only imagine in a class there are two Toppers right like sometimes let&#39;s say there are two students RAM and shyam in one test Ram gets 99.9 and charm got 99.8 the next one only Sean got 99.9 Ram got 99.8 so these two are constantly fighting fighting fighting fighting fighting and you can never understand which one is the topper which one is exactly the topper because in one exam the ram is a Topper in my other exam is the topic so every time Ram gets more mass Ram is like hey see I&#39;m the topper charm is like so what bro next exam I&#39;ll show you this is exactly the case for them also the forest ones are like hey we are the ones who are the Ultimate Energy shells you know the 3D ones are like we&#39;re just right next to you don&#39;t worry about it we are right here yeah so the energy gap is so low the energy gap between them is so low that the moment Scandium loses one the other two would it is easier for them to lose the other two and then attain stability plus three is more viable option for them okay plus three is more viable option for them same for zinc the moment zinc loses plus zinc loses two electrons it is three D ten and then it&#39;s like try giving me more energy I&#39;m not gonna give away the electron only so plus 2 is a more viable option okay all right but otherwise you get to see a lot of variable oxidation state why do you say variable oxidation say once again the similar energies of NS and N minus 1 see the 4S and 3D orbitals they have such close energy gaps that you know the moment you take away one electron the 3D is like I also have electrons why can&#39;t you take it from me also and that results in variable oxidation state do we understand this do we understand this okay that results in the variable oxidation state now in the upcoming classes we will be learning about standard electrode potential we will be learning about other properties that are there yes uh so please stay tuned to this channel if you are a regular in this channel then amazing don&#39;t forget to like this video but if you are new to this channel don&#39;t forget to share and subscribe with your friends because the more students you share with more students get benefited and of course don&#39;t forget to like the video yeah I have put in a lot of efforts to take this session and will be amazing if you like the video it&#39;ll give me a little bit of happiness a lot of happiness in that so with this note everybody I&#39;ll see you soon with the next session and all the very best for your board exam start preparing right now bye

Transcript for:Understanding DNF Block Elements in Chemistry

Transcript for:
Understanding DNF Block Elements in Chemistry