Some atoms have nearly eight electrons in their valence shell and can gain additional valence electrons until they have an octet. When these atoms gain electrons, they acquire a negative charge because they now possess more electrons than protons. Negatively charged ions are called anions.

What happens when you gain a valence electron?

An atom that loses one or more valence electrons to become a positively charged ion is known as a cation, while an atom that gains electrons and becomes negatively charged is known as an anion.

What elements will gain valence electrons?

Atoms of nonmetals tend to gain electrons in order to fill their outermost principal energy level with an octet. Atoms form compounds in ways that give them eight valence electrons. Metals tend to lose electrons to achieve this configuration. Nonmetals tend to gain electrons to achieve this configuration.