Question

Radiation is spontaneously emitted from hydrogen-3 nuclei, but radiation is not spontaneously emitted from hydrogen-l nuclei or hydrogen-2 nuclei. Which hydrogen nuclei are stable?(1) nuclei of H-l and H-2, only(2) nuclei of H-l and H-3, only(3) nuclei of H-2 and H-3, only(4) nuclei of H-l, H-2, and H-3

Answer 1

Answer : Option 1) nuclei of $H^{1}$ and nuclei of $H^{2}$ only.

Explanation : Radiation is spontaneously emitted from nuclei of $H^{3}$ because this isotope of hydrogen is highly radioactive as compared to other isotopes of hydrogen namely; nuclei of $H^{1}$ and nuclei of $H^{2}$.

They have much stable nucleus as compared to nuclei of $H^{3}$.

The more it is unstable the more radiations will be emitted from its nucleus.

Answer 2

The answer is (1) nuclei of H-1 and H-2, only. Because the nuclei of hydrogen-3 can spontaneously emit radiation. So it is not stable. While other two will not spontaneously emit radiation. So these two are stable.