monatomic

/ˌmɑnəˈtɑmɪk/
adjective
  1. Consisting of a single atom.
    • Helium is a monatomic gas, meaning each particle is a single atom.
    • In chemistry class, we learned that noble gases are monatomic elements.
    • The monatomic structure of argon makes it very stable and unreactive.
Antonyms
What does "monatomic" mean? | whatsthatwordmean | whatsthatwordmean