Which term best describes a molecule that consists of two identical atoms?

Which term best describes a molecule that consists of two identical atoms?

• A. Diatomic
• B. Molecular
• C. Diatom
• D. Polyatomic

Answer: (A)

Two atoms in a single molecule define its name: diatomic means two atoms. When those two atoms are the same element, the molecule is a homonuclear diatomic molecule, like O2 or N2. This is the exact situation described—a molecule that consists of two identical atoms. The word molecular is too general because it can refer to any number of bonded atoms, not just two. Diatom isn’t a standard term used for describing such molecules, and polyatomic refers to more than two atoms. So diatomic is the precise label for a two-atom molecule, especially when the atoms are identical.

Two atoms in a single molecule define its name: diatomic means two atoms. When those two atoms are the same element, the molecule is a homonuclear diatomic molecule, like O2 or N2. This is the exact situation described—a molecule that consists of two identical atoms. The word molecular is too general because it can refer to any number of bonded atoms, not just two. Diatom isn’t a standard term used for describing such molecules, and polyatomic refers to more than two atoms. So diatomic is the precise label for a two-atom molecule, especially when the atoms are identical.