Question

All of the following elements have valency less than or equal to 1, except

• A.
  Ne
• B.
  He
• C.
  F
• D.
  B

Answer 1

The correct option is D

B
Valency is the combining capacity of the atoms of elements to attain a fully-filled outermost shell. The elements attain eight electrons in their outermost shell by sharing, gaining or losing electrons.

The electronic configuration and valency of given elements is as follows:

$\begin{array}{ccc}\text{Element}& \text{Electronic Configuration}& \text{Valency}\\ \text{Ne}& \text{2,8}& \text{0}\\ \text{He}& \text{2}& \text{0}\\ \text{F}& \text{2,7}& \text{1}\\ \text{B}& \text{2,3}& \text{3}\end{array}$


Hence, the correct answer is option (d).