molecular formula
Scientific term used in chemistry to denote the number and type of atoms in a molecule.
The molecular formula of water is H₂O.
この化合物の分子式を調べてください。
Please look up the molecular formula of this compound.
組成式 (empirical formula) gives the simplest whole-number ratio of atoms, whereas 分子式 gives the actual number of atoms in a molecule.
Compound of 分子 (ぶんし, 'molecule') and 式 (しき, 'formula').