Which isotope of hydrogen is radioactive, emits low-energy beta particles, and has a half-life of approximately 12.3 years?

💡 Solution & Explanation

Tritium is a radioactive isotope of hydrogen containing one proton and two neutrons in its nucleus, undergoing beta decay to helium-3 with a half-life of 12.3 years. Protium is the most abundant stable hydrogen isotope with a single proton and no neutrons. Deuterium is a stable heavy hydrogen isotope possessing one proton and one neutron. Hydride refers to the negative ion of hydrogen rather than a distinct nuclear isotope.