protium

[proh-tee-uh m, -shee-uh m] /ˈproʊ ti əm, -ʃi əm/
noun, Chemistry
1.
the lightest and most common isotope of hydrogen. Symbol: H 1.
Origin
1930-35; prot- + -ium
British Dictionary definitions for protium

protium

/ˈprəʊtɪəm/
noun
1.
the most common isotope of hydrogen, having a mass number of 1
Word Origin
C20: New Latin, from proto- + -ium
protium in Medicine

protium pro·ti·um (prō'tē-əm, prō'shē-)
n.
See hydrogen-1.

protium in Science
protium
  (prō'tē-əm, -shē-əm)   
The most abundant isotope of hydrogen, having an atomic mass of 1. Its nucleus consists of a single proton. See more at hydrogen.
Encyclopedia Article for protium

isotope of hydrogen (q.v.) with atomic weight of approximately 1; its nucleus consists of only one proton. Ordinary hydrogen is made up almost entirely of protium.

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