出典:Wikipedia
出典:『Wikipedia』 (2011/06/06 02:59 UTC 版)
Deuterium, also called heavy hydrogen, is one of two stable isotopes of hydrogen with a natural abundance in Earth's oceans of about one atom in 6,400 of hydrogen (~156.25 ppm). Deuterium accounts for approximately 0.0156% (or on a mass basis: 0.0312%) of all naturally occurring hydrogen in Earth's oceans, while the most common isotope (protium) accounts for more than 99.98%. The abundance of deuterium changes slightly from one kind of natural water to another (see VSMOW).