### Q.28:- (i)An atomic orbital has n = 3. What are the possible values of *l* and m_{l} ?

(ii) List the quantum numbers (m_{l} and *l* ) of electrons for 3d orbital.

(iii) Which of the following orbitals are possible?

1p, 2s, 2p and 3f

**Answer:-**

(i) For a given value of n, *l* can have values from 0 to (n-1).

∴ For n = 3 , l = 0, 1, 2

For a given value of *l*, m_{l} can have (2*l*+1) values.

When *l* = 0, m = 0

*l* = 1, m = – 1, 0, 1

*l* = 2, m = – 2, – 1, 0, 1, 2

*l* = 3, m = -3, -2, -1, 0, 1, 2, 3

(ii) For 3d orbital,* *n = 3*, l* = 2.

∴ For *l* = 2

m_{2} = -2, -1, 0, 1, 2

(iii) 1p is not possible because when n = 1, *l *= 0. (for p, *l* = 1)

2s is possible because when n=2,* l* = 0,1 (for s, *l*=0)

2p is possible because when n=2,* l* = 0,1 (for p, *l*=1)

3f is not possible because when n=3, *l *= 0, 1 , 2 (for f, *l*=3)