How many electrons in an atom may have the following quantum numbers?

(a) n = 4, ms= – 1/2


(b) n = 3, l = 0

(a) Total number of electrons in an atom can be found out by the following relationship

ne = 2n2


Total no of electrons when n=4, then n = 2× 42 = 32 & half of them have ms = -1/2


(b) When n = 3, L=0 means 3s orbital which can have 2 electrons.


33