'O<sub>2</sub> is a diatomic one of these units of a pure substance; H<sub>2</sub>O is polyatomic'
a molecule
SCIENCE TERMS: O<sub>2</sub> is a diatomic one of these units of a pure substance; H<sub>2</sub>O is polyatomic
O<sub>2</sub> is a diatomic one of these units of a pure substance; H<sub>2</sub>O is polyatomic
O<sub>2</sub> is a diatomic one of these units of a pure substance; H<sub>2</sub>O is polyatomic
SCIENCE TERMS
a molecule
SCIENCE TERMS