Question

What do you think? Should hydrogen be placed in the group 17 of halogens or group 1 of alkali metals in the modern periodic table?

Answer 1

Because it resembles both halogens and alkali metals, hydrogen is classified in groups 1 and 17. As a result, Mendeleev's periodic chart did not assign hydrogen a definite position.

On the other hand, hydrogen readily contributes an electron to form a stable cation (H⁺), but it finds it difficult to form a stable anion (H⁻), the hydride ion. Therefore, in the current periodic table, group 1 is a better place for it than group 17.