Atoms of reactive non-metal elements gain electrons in some of their reactions to form negative ions. The ions formed have a full outer electron shell, so are very stable.

Are non-metals reactive or stable?

Properties of nonmetals include a relatively low boiling point, so many nonmetals are gases. Nonmetals are also poor conductors of heat, and solid nonmetals are dull and brittle. Some nonmetals are very reactive, whereas others are not reactive at all. It depends on the number of electrons in their outer energy level.

How do nonmetals gain stability?

Ionic bonds form when a nonmetal and a metal exchange electrons, while covalent bonds form when electrons are shared between two nonmetals. ... Atoms form covalent bonds in order to reach a more stable state. A given nonmetal atom can form a single, double, or triple bond with another nonmetal.