# Which of the following forms of hydrogen emits low energy b- particles?

a. Proton H+

b. Deuterium $$_{1}^{2}\textrm{H}$$

c. Protium $$_{1}^{1}\textrm{H}$$

d. Tritium $$_{1}^{3}\textrm{H}$$

Tritium isotope of hydrogen is radioactive and emits low energy b particles. It is because

of high n/p ratio of the tritium which makes the nucleus unstable.