Question

An element $X$ (atomic number $17$) reacts with an element $Y$ (atomic number $20$) to form a divalent halide.

Element X is :

• A. a metal
• B. a non-metal
• C. a metalloid
• D. None of these

Answer 1

The correct option is B a non-metal

As atomic number of X is 17 it will have 17 electrons, i.e. $1s^{2}2s^{2}2p^{6}3s^{2}3p^5$.

From this we could understand that it will be in the period 3 because of outer most shell is 3 and as it has only one unpaired electron and has to accept only one electron to get octet configuration.

Hence, X is non metal as it accepts electrons.

Hence the correct option is B.