tritium
/ˈtrɪtɪəm/noun
mass noun
- Chemistry a radioactive isotope of hydrogen with a mass approximately three times that of the usual isotope. (Symbol:
T )【化】（氢的放射性同位素）氚（符号： T）。
Discovered in 1934, tritium has two neutrons as well as a proton in the nucleus. It occurs in minute traces in nature and can be made artificially from lithium or deuterium in nuclear reactors; it is used as a fuel in thermonuclear bombs.
词源
1930s: from modern Latin, from Greek tritos 'third'.