Question

Nonmetals in the periodic table have a negative oxidation number. Which statement best explains why?

Answer 1

Nonmetals gain one or more valence electrons to become stable, giving them a negative oxidation number.

Explanation:

Atoms want to have full outer shells of electrons. Nonmetals become more stable by adding one to three valence electrons to their outer shells. When they gain negative electron(s), they acquire an overall negative charge.

Answer 2

They have a negative oxidation number because nonmetals gain electrons, thus making them negatively charged ions (anions). Metals become cations and have a positive charge because they lose electrons.