Tritium, a radioactive isotope of hydrogen, emits which of the following particles ?

The correct option is Beta (β⁻).

Step-by-Step Explanation:

Tritium (${}_1{}^{3}H$) is a radioactive isotope of hydrogen. The nucleus of a tritium atom contains 1 proton and 2 neutrons, giving it a mass number of 3. Because it has an excess of neutrons, the nucleus is unstable.

To achieve stability, tritium undergoes radioactive decay. Specifically, it undergoes beta-minus (${\beta }^{-}$) decay. During this process, one of the neutrons inside the tritium nucleus decays into a proton. To conserve charge and other quantum numbers, a high-energy electron (a beta particle, ${\beta }^{-}$) and an electron antineutrino (${\overline{\nu }}_e$) are emitted from the nucleus.

The nuclear equation for the radioactive decay of tritium is:
${}_1{}^{3}H\to {}_2{}^3\mathrm{He}+{}_{-1}{}^{0}e+{\overline{\nu }}_e$
This decay transforms the tritium atom into a stable helium-3 (${}_2{}^3\mathrm{He}$) atom.

Therefore, the radioactive isotope tritium emits beta (β⁻) particles during its decay.