protium

from Ancient Greek πρῶτος (prôtos, “first”) + -ium

protium (plural protiums)

1. (physics) The lightest and most common isotope of hydrogen, having a single proton and no neutrons: ¹₁H

   So far there are no differences among the protiums extracted at various labs, except for concentration levels.

2. An atom of this isotope.

• hydrogen-one, hydrogen-1, H-1
• unium-one, unium-1, U-1

• element one, element 1
• hydrogen (H)
• unium (U)

• (isotopes of hydrogen): deuterium, tritium, quadrium

• proton (p)

• Elementymology

• protium on Wikipedia.Wikipedia

From Ancient Greek πρῶτος (prôtos, “first”) +‎ -ium.

• Hyphenation: pro‧ti‧um

protium n (uncountable)

1. protium

From English protium.

• IPA^(key): /ˈprotium/, [ˈpro̞t̪ium]
• Rhymes: -otium
• Syllabification^(key): pro‧ti‧um

protium

1. (physics) protium

• (Classical) IPA^(key): /ˈproː.ti.um/, [ˈproːt̪iʊ̃ˑ]
• (Ecclesiastical) IPA^(key): /ˈprot.t͡si.um/, [ˈprɔt̪ː͡s̪ium]

prōtium n (genitive prōtiī or prōtī); second declension

1. protium

Second-declension noun (neuter).

¹Found in older Latin (until the Augustan Age).