diatomic molecule
Scientific term for a molecule composed of exactly two atoms, such as O₂ or N₂.
Oxygen exists as a diatomic molecule.
Monatomic molecule; consists of a single atom, unlike 二原子分子 which has two.
Polyatomic molecule; consists of three or more atoms, in contrast to the two-atom structure of 二原子分子.
Compound of 二 (two) + 原子 (atom) + 分子 (molecule), directly describing a molecule made of two atoms.