单词	protium
释义	protium /ˈprəʊtɪəm / noun [mass noun] Chemistry The common, stable isotope of hydrogen, as distinct from deuterium and tritium.The three isotopes are sometimes known by the names of protium, deuterium, and tritium.... His hypothesis was that the lighter and more abundant protium isotope would evaporate more quickly than the heavier hydrogen - 2 isotope. Origin 1930s: modern Latin, from Greek prōtos 'first'.
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