(i) ‘n’ refers to the principle quantum number

‘l’ refers to the azimuthal quantum number

‘m’ refers to the magnetic quantum number

l can have any value from to n – 1.

So, for n= 3, the permissible value of l = 0, 1, 2

M can have any value from –l, -l+1 ………..0, 1 ……… l

For l = 0

m = 0

For l = 1

m = +1, 0, -1

For l = 2

m = +2, +1, 0, -1, -2

(ii) When l = 2 the value of m = -2, -1, 0, +1, +2

Now, for the 3d orbital:

Principal quantum number [n] = 3

Azimuthal quantum number [L] = 2

Magnetic quantum number [mL] = -2, -1, 0, 1, 2

(iii) For a given value of n the value of l can range from 0 to n-1
So for n =1, l = 0

Thus, 1p is not possible
For n = 2, l = 0 and 1

Therefore, 2s and 2p are possible orbitals.
For n = 3, l = 0, 1 and 2

So 3p is not possible.