Question

An element X lies in the third period and group 17. Find out name of the element.

Answer 1

Chlorine is an element X lies in the third period and group $17.$

The electron configuration of an element describes how electrons are distributed around an atom .

Figuring out the element:

1. The element lies in group $17$ , so it is a halogen.
2. The element lies in period $3$, so it has electronic configuration $1s^{2}2s^{2}2p^{2}3s^{2}3p^{2}3p^5$ or $\left[Ne\right]3s^{2}3p^5$.
3. The second halogen being Chlorine, it has the same configuration as above, so element X is $Cl$.