Question

A neutral atom of an element has 2K, 8L, 11M and 2N electrons. The number of s-electron in the atom are:

• A. 2
• B. 8
• C. 10
• D. 6

Answer 1

The correct option is B 8

The neutral atom has $2K,8L,11M$ and $2N$ electrons.

$K\to 1s^2$

$L\to 2s^2,2p^6$

$M\to 3s^2,3p^6,3d^3$

$N\to 4s^2$

The total number of $s-$electron in the atom $=8$

Hence, the correct option is $B$