Question

Given below are the electronic configurations of some elements:

(a) 2,8,3

(b) 2,8,18,5

(c) 2,8,7

(d) 2,8,18,8,1

(e) 2,8,2

(f) 2,5

(g) 2,8,18,8

Answer the following:

(c) which is an inert gas?

Answer 1

1. An element which has all of its octet complete, and there are no unfilled shells, is known as noble gas.
2. The noble gases are inert in nature, and they do not react with other elements as the criteria of bonding is to complete the octet, and they already have fully filled octet.
3. The element having electronic configuration equal to 2, 8, 18, 8 is a noble gas as all of its shell are fully filled.
4. Therefore, the option (g) 2, 8, 18, 8 is correct.

Electronic configurations of some elements that are not inert gases

(a) $2,8,3$ - Aluminium belongs to group $13$ and period $3$.

(b) $2,8,18,5$- Arsenic belongs to group 15 and period $4$.

(c) $2,8,7$- Chlorine belongs to group $17$ and period $3$.

(d) $2,8,18,8,1$- Rubidium belongs to group $1$ and period $5$.

(e)$2,8,2$- Magnesium belongs to group $2$ and period $3$.

(f)$2,5$- Nitrogen belongs to group $15$ and period $2$.