Question

Which of these subshell designations are possible and which are impossible?

1s 0p 2d 3f 4f

Answer 1

Principle quantum number is represented by n,

It can take values n = 1,2,3....

Orbital angular momentum quantum number is resprented by

lt can take values = 0,1,...(n-1)

Value of is dependent on n,

for eg. n = 2 , can take values upto (n-1) thus = 0,1

= 0 means electron is in s shell

= 1 corresponds to p shell

= 2 corresponds to d shell

= 3 corresponds to f shell

s,p,d,f corresponds to = 0, 1, 2, 3

Now consider

1) 1s , here 1 is principal quantum number n, and

s subshell corresponds to orbital angular quantum number

1s n = 1 , corresponding value of = 0

subshell for n = 1 is , 1s

1s is possible subshell

2) 0p    n = 0 ,

n can never be zero,

0p is impossible subshell

3) 2d n = 2 , corresponding values of = 0 , 1

All possible subshells fo n = 2 is, 2s and 2p

thus, 2d is impossible

4) 3f n = 3 , that will give = 0, 1, 2

Possible subshells are 3s , 3p and 3d

3f is impossible subshell

5) 4f n = 4 . corresponding values of = 0, 1, 2, 3

Possible subshells are 4s, 4p, 4d, and 4f

4f is possible subshell.

Possible subshells - 1s, 4f

Impossible subshells - 0p, 2d, 3f