text: Tritium (hydrogen-3) is produced by neutron irradiation of Li:
  :Li + n → He + H
  Tritium has a half-life  days (approximately 12.32 years) and it decays by beta decay. The electrons produced have an average energy of 5.7 keV. Because the emitted electrons have relatively low energy, the detection efficiency by scintillation counting is rather low. However, hydrogen atoms are present in all organic compounds, so tritium is frequently used as a tracer in biochemical studies.