Atomic Structure part 28

Added: 2026-05-12

[00:00:00]already said you the distance from the nucleus increases in this manner so s substitute is nearer to the nucleus then p subshell then d subshell than the absorption but the energy is opposite listen carefully the distance increases in this way the s substitute is nearer than p substitution d substitution and m but the energy is just opposite energy is just opposite f subshell is having higher energy than the d then p then s got it energy increases in this manner all right energy increases in this way in this way so that is s substitution which is nearer to the nucleus is having lower energy all right the lower image then the p substitute this optional exception just like ah what you can say in the this cell it is there the the energy of the first shell is the lowest the ground state then after that what happens energy increases here also same thing as subshell which is nearer to the nucleus is having the lowest energy then after that the energy increases but the distance in prison in this manner now you might be wondering why we have uh why we are saying spdf spdf y from where we got the word as pdf s has come from the word shah p has come from the word principle d has come from the word diffuse and f has come from the word fundamental generally this 4 is generally used because whatever the number of atoms we are having the number of elements which are discovered that is 118 elements maximum we can have in the periodic table today so spdf is sufficient this number of subshells is substance g h is still not used even f sub shell is also not being completed completely f sub shell is also not being completed you can say that clear so hence g and h no question about it right so that you must understand it first so hence we are not including the g and exception so s has come from the word sharp p has come from the word principle d has come from the word diffuse and f has come from the word that is nothing but fundamental we can say that f has come from the word so in this way what are these these are the old name of the spectral series old name of the spectral series which we today call it as lyman balmer bastian brackett p fund that's that's the old name of those spectral series don't think this is the name of the scientist no these are the old name of the spectral series which we have already studied earlier all right that is sharp principle diffuser fundamental we can say that clear so you came to know that is the designation of the substance you came to know the distance from uh the electrons uh distance of the this substance from that of the nucleus the distance in this way the energies you came to know energies also increases in this manner got it clear so next the number of electrons in a given subshell also you can know the maximum number of electrons in a given subshell you came to know what okay now you will see that is nothing but the shape of the given suction the shape now s subshell is spherical now sphere i cannot draw it here in a two-dimensional i'll draw it a circle only all right so you can you have to understand this is an assumption which is spherical but it is a circle but you have to understand the spherical assumption we can say that then p sub shell is dumbbell dumbbell dumbbell this option is let me write it here spherical assumptions the shape is spherical p sub shell is dumbbell we can say this is the internuclear axis the line which i have done here also we can have the internuclear axis inter nuclear axis because these are nucleus is there the line which passes through is known as what inter nuclear axis that's an imaginary line minute so in this way this is p subshell which is dumbbell we can say that the shape is dumbbell shape now d sub shell is double dumbbell d substitute this is double double the disruption is clear this is this option which is double tumble double you can see this is dumbbell this is double double two doubles of it double dumbbell and f sub shell we do not know the shape because it is complex in nature f suction is complex in nature so we do not know the shape of the absorption s is spherical t is double d is double double we can say that we do not know the shape of the absorption because it is complex in nature surfacing all right so in this way we came to know now next we will see the angular momentum of an electron in a given subshell in a given sub shell we have already said the angular momentum of a particular shell which is mbr is equal to h by 2 pi all right but in a given sub shell what is the angular momentum angular momentum is nothing but root over of l into l plus 1 whole into h by 2 pi now this is not there inside this particular root all right root over of l into l plus 1 whole into h by 2 pi like suppose if an electron is present in s subshell the value of n is what zero if an electron is present in p subshell value of l is what one if an electron is present in d subshell value of n is what two you know that already studied h is the language constant six point six two six ten to the power minus thirty four joules and pi is 22 by 7 you know it so this is the angular momentum of an electron in a particular sub shell so you see that right in this way you can calculate angular momentum so everything we have calculated the number of subshells in a particular shell the maximum number of substance we have calculated the angular momentum of an electron the shape of the elec what you can say various options the relative energies because as i said s sub shell is nearer to the nucleus is always having lowest energy then as you move away that is s p d f g h it is increasing but again i repeat g h is not required till now because whatever the atom is discovered there are 118 elements all the 118 elements is not completely discovered so whatever the elements has been discovered whatever the atom has been discovered if subshell is not completely used then what to talk about g and h substrate when f will be used or complete then only we will have the g and h now isn't it because first when the filling of the electron takes place you will see it when you write electronic configuration first s subshell is filled the lowest energy then p subshell is split and d substitute is filled and then m substitution all right so f sub shell is not completely filled till now we can say that here so there is no question of g and its option now next is uh after that we will just have a look of the electrons in a particular shell and the subshell we can say that clear now first shell n is equal to 1 has got only one suction assumption first n is equal to one means l is equal to zero l max is zero so one suction zero means assumption all right listen carefully now when i say n is equal to two second shell l max is one what i say maximum value is one but the minimum value is what zero minimum value is zero so hence you are having two sub shells listen carefully here n is equal to two we are having two subshell one is s another is p one is s another is p now here we need to give the designation of a particular subshell so designation units are already given okay fine but along with the shell we have to give the designation so when we give the designation of a cell along the subshell along with the cell then what is that it is nl what i said designation of the subshell when we give it then we also use it the shell why because suctions are present inside the shell mind it so we have to use that particular shell also now here when we put the value we put the designation designation means when n is 1 and l is 0 let us say when n is 1 l is 0 then 1 s we write it as means first shell has only s option what is it only one subshell s all right clear fine next is when we write n is equal to 2 where n is equal to let me write it above here n is equal to 1 then designation l is equal to 0 so designation is what 1 s 1 s designation why why i said you because always sub-shells are inside the shell so we have to take the cells also because the designation is nl where l we give the symbol symbol not the value now next we are taking in this way no need to ask any question about it so when n is equal to 2 l will have that is 2 subshell the maximum value is 1. if you remember it i have written l max is equal to 1 but 1 is minimum value if it is 1 means when a value is zero so we can have l is equal to two subshell zero and one if it is zero then it is nothing but two s if it is one then it is nothing but two p because one means p substitute zero means s suction don't get confused i am saying repeatedly n2 means they are having two subshell one is s another is p because l max is one maximum value of l is one minimum value can be zero so it can be two s and two p similarly when n is equal to 3 l we can have 0 1 and 2 so 0 means it is 3 s then it is 3 p and this one is 3 d all right n is 3 l can be 0 1 2 so 0 means 3s and l 3s then if 1 it is then 3p then 2 means it is 3d that means third shell will have three suction third shell will have three suctions this is your third shell we have three substance what is that s p and d we consider then fourth shell will have four subshell fourth shell will have four subshells l is equal to zero one 2 3 because if n is 4 maximum value of i is 3 so minimum value will be 0 1 and 2 so 0 means it will be what nothing but 4 s this will be 4 b this will be 4 d and this will be 4 f we can say that i've written f here f i've written f so fourth child i don't have the place similarly fourth shell will have four shall be there how many sub shells four s four p four d four f got it in this way we got the designation of a particular cell and the subshell we can say this is about your azimuthal quantum number so to say click ok you