Question

In the introduction of the chapter metal and non-metals there is a subtopic called microscopic world. In the video they are talking about shells surrounding the protons. In my school I am being taught that that the third shell has a valency of 8 but in the video they are saying that the third shell has 18 valency. Please tell me the solution for the same. Thank you.

Answer 1

valency of third shell = 18

We have a formula for calculating the valency of Nth shell,
V= 2 x N x N
where
V-->valency
N--> shell number

Eg:

• valency of the first shell ( N=1) = 2x1x1 = 2
• valency of the second shell (N=2) =2x2x2=8
• valency of third shell (N=3) =2x3x3=18
• valency of 5th shell (N=5) = 2x5x5 = 50

Similarly you can calculte the valency of required shell.

Thanks