Question

Given below are four elements with their atomic numbers

Element	Atomic number
A	16
B	11
C	3
D	14

Which of the above elements is a metalloid ?

Answer 1

The electronic configuration of all the elements are following:-

$A=2,8,6$

$B=2,8,1$

$C=2,1$

$D=2,8,4$

Elements $A$ have a tendency to gain electron so it behaves as non-metal.

Elements $B$ and $C$ have a tendency to lose electrons and become stable by acquiring octet, so these are metals.

Element $D$ can neither lose nor gain 4 electrons to become stable. Hence it is metalloid.

So, the answer is $D$