Question

Which of the subshell designations are possible and which are impossible? 1) 2p 2) 1f 3) 3s 4) 1d 5) 1p

Answer 1

The sub shell designations 2p, 3s are possible while the sub shell designations like 1f, 1d and 1p are not possible.

Answer: Options 1 and 3 are possible but 2,3,5 are impossible

Explanation:

The sub shell designations are represented as nL, where n is the principle quantum number and l is the azimuthal quantum number of every shell. It is known that if n is the principle quantum number of a shell, then $2n^{2}$ number of electrons can occupy that particular shell.

Also, the azimuthal quantum number L has a limitation that it can only be in the range of 0 to (n-1) values [i.e. (0< L < (n-1))]. Each values of L denotes subshell and they can be represented as alphabets as s, p, d, f, g, h.

So, in this case, the option 2p represents the n = 2 and L=1 which matches the limitations of azimuthal quantum number i.e. (0< L < (n-1)) . Similarly, the option 3s consists of n = 3 and L = 0 which matches the limitations of L i.e. (0< L < (n-1)). So, the subshells 2p and 3s are possible.

But the remaining options 1f, 1d and 1p are not possible because it fails the limitations criteria of L i.e. (0< L < (n-1)). In 1f, n = 1 and L = 3, so L > n which is not at all possible according to quantum levels. Similarly for 1d, n = 1 and L = 2 and 1p, n = 1 and L = 1, both of these hinders the limitations condition of azimuthal quantum number.