# What states that atoms tend to gain, lose or share electrons until they are surrounded by eight valence electrons?

The $\text{octet rule}$, which is more a rule of thumb than an actual chemical principle.
Main-group elements tend to form compounds in which the participating atoms are surrounded by $\text{8 electrons}$. There are many exceptions to the rule, but often we can rationalize the chemistry of the exceptions in terms of filling the valence shell of the participating atoms with 8 electrons.