How do atoms become more chemically stable?

For an atom to become totally stable, it needs to have a full outer shell. To do this, two or more atoms will share or give away electrons to each other in a process called bonding.

Explanation:

When an atom loses or gains an electron, it becomes an ion. If it gains an electron, it's a cation, and if it loses one, it's an anion. This happens most commonly in chemical reactions, in which atoms share electrons to form a stable outer shell of 8. For example, the water molecule consists of two hydrogen atoms and an oxygen atom.