Why does an atom want to be stable?

Answer 1

An atom must be stable because it must not react with other atoms to change it's state.

Answer 2

Atoms want to be stable because stability leads to a lower energy state, which is more favorable. When atoms are stable, their outer electron shells are filled or partially filled, which results in a more balanced state. Atoms achieve stability by gaining, losing, or sharing electrons to reach a more stable electron configuration.