tritium

n.

1.

(Chem.) A radioactive isotope of hydrogen having one proton and two neutrons in the nucleus. It decays spontaneously to Helium-3 by the emission of an electron (beta ray), with a half-life of 12.3 years. Symbol 1H3. Atomic weight 3.01605 (C-12 = 12.0000). It is one of the radioisotopes commonly used to label chemical compounds for use as tracers in biochemistry and chemistry. It is also used as one of the fusionable components of a hydrogen bomb.

Noun

1.

tritium - a radioactive isotope of hydrogen; atoms of tritium have three times the mass of ordinary hydrogen atoms

atomic number 1, H, hydrogen