Question

The atomic number of an element 'y' is 20. The electronic configuration of the ion having inert gas configuration is:

• A. 2, 8, 10
• B. 2, 18
• C. 2, 10, 8
• D. 2, 8, 8

Answer 1

The correct option is D 2, 8, 8

Electronic configuration is the number of electrons present per shell.

Inert gases have fully filled valence shell and does not react with other atoms to form molecule. $2,8,8$ is electronic configuration of inert gas which shows that these gases do not participate in reactions with other elements.

Example:-

(i) Electronic configuration of Argon

$Ar(2,8,8)$

(ii) Electronic configuration of Neon

$Ne(2,8)$

This shows that inert gases are quite stable.