Question

All elements tend to obey octet rule except hydrogen. Why is it so?

• A. Because hydrogen is in the gaseous state.
• B. Because hydrogen can accommodate a maximum of 2 electrons in its valence shell.
• C. Because hydrogen is a metal.
• D. The question is wrong. Hydrogen obeys the octet rule.

Answer 1

The correct option is B Because hydrogen can accommodate a maximum of 2 electrons in its valence shell.

Because hydrogen can accommodate a maximum of 2 electrons in its valence shell (K-shell $\to$ $2n^2=2$ as (n=1 for K-shell)), thus it does not obey the octet rule.
By obtaining 2 electrons in its valence shell, it attains the nearest noble gas configuration, i.e., of helium.