Question

an atom has 2k, 8L, 13M, 2N electrons. write electronic configuration of atom. what is the number of unpaired electron in it? what is th number of electron having l = 0 in it?

Answer 1

Dear Student

According to the given data of KLMN the atomic number of the atom = 25

So, the electronic configuration will be = $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}3d^{5}4s^2$
This is the electronic configuration of magnesium.

Total unpaired number of electrons are = 5 as d orbital has 5 subshell and first of all, all the subshells must be singly occupied.

The azimuthal quantum number (l) is zero for "s" orbital, and hence the number of electrons for this electronic configuration which have l = 0 are 8.

Regards