# Which of the following forms of

Question:

Which of the following forms of hydrogen emits low energy $\beta^{-}$particles?

1.  Proton $\mathrm{H}^{+}$

2. Deuterium ${ }_{1}^{2} \mathrm{H}$

3.  Protium ${ }_{1}^{1} \mathrm{H}$

4. Tritium ${ }_{1}^{3} \mathrm{H}$

Correct Option: , 4

Solution:

Tritium isotope of hydrogen is radioactive and emits low energy $\beta^{-}$particles. It is because of high $\mathrm{n} / \mathrm{p}$ ratio of tritium which makes nucleus unstable.