Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
The octet rule is a chemical rule of thumb that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells, giving them the same electronic configuration as a noble gas.
Related terms
Valence Shell: The outermost electron shell of an atom which participates in bonding.
Noble Gases: Elements in group 18 on the periodic table known for their full set of electrons in their outer shell making them stable and unreactive.
Electron Configuration: The distribution of electrons among energy levels or orbitals in an atom.