Definition of protium in English:

protium

noun

mass nounChemistry
  • The common, stable isotope of hydrogen, as distinct from deuterium and tritium.

    • ‘His hypothesis was that the lighter and more abundant protium isotope would evaporate more quickly than the heavier hydrogen - 2 isotope.’
    • ‘The three isotopes are sometimes known by the names of protium, deuterium, and tritium.’

Origin

1930s: modern Latin, from Greek prōtos ‘first’.

Pronunciation

protium

/ˈprəʊtɪəm/