Question

If an atom has 2 electrons in its outermost shell. Which of the following options can be the atomic number of that atom?

• A. 10
• B. 11
• C. 12
• D. 13

Answer 1

The correct option is C

12

The maximum number of electrons that can be accommodated in any shell according to Bohr and Bury is $2$ $\times$ $n^2$ where n is the shell number

K-Shell will be=$2\times 1^2$=$2$

L- Shell will be= $2\times 2^2$ = $8$

The maximum number of electrons that can be filled in the shell K, L, M, N respectively are 2, 8, 18, 32.

So, as per this rule, the 2,8,2 is the correct distribution and hence, the suitable atomic number of the element with 2 outermost electrons would be 2+8+2 = 12.