Question

How does the location of hydrogen on the periodic table differ from other nonmetals?

Answer 1

It's special, because it has only one electron, while the ideal "noble gas" configuration (helium) would call for two.

Explanation:

So in one way it could 'try' to gain an electron as any element from halogen group (F-Cl-Br...) would do.
On the other hand it could lose its one electron, in which case it would belong to the alkali metals (Li-Na-K...).

In practice, `H` mostly shares its electron, either by covalent bonds, or by donating an electron and working together with `H_2O` to form the `H_3O^+` or 'acid' ion.

In short, `H` is too special to to put it in a specific Group.