Consisting of one atom.
- ‘Data for monatomic gases like argon and helium give exact agreement, and many diatomic gases show experimental results in close accord with the theory.’
- ‘For example, aluminum, helium, and sodium are monatomic elements, or elements whose atoms can exist alone, without forming molecules.’
- ‘Although the most common anion formed by oxygen is monatomic, oxygen can also form diatomic ions known as peroxides and superoxides (monovalent).’
- ‘Those compounds should be abundant on a planet, but pure oxygen, whether monatomic or molecular, should be vanishingly scarce - as it is, in fact, on Mars and Venus.’
- ‘Dalton had used Ockham's Razor to assume elemental gases were monatomic.’