Question

Why is the alpha, beta, or gamma decay of an unstable nucleus unaffected by the chemical situation of the atom, such as the nature of the molecule or solid in which it is bound? The chemical situation of the atom can, however, have an effect on the half-life in electron capture. Why is this?

Short answer

Energies of various $eV$handle by the chemical situations. But the $\alpha ,\beta$, and $\gamma$ decays of an unstable nucleus handle very high energies within the range of $KeV$ and $MeV$. The chemical situation affects the nucleus so it is difficult for a small energy change. The chemical situation changes the probability of a K-shell electron being available for electron capture.

Step-by-step solution

Explain the chemical situations.

Energies of various $eV$handle by the chemical situations. But the $\alpha ,\beta$, and $\gamma$decays of an unstable nucleus handle very high energies within the range of $KeV$and $MeV$. Because the chemical situation affects the nucleus so it is difficult for a small energy change.

Explain the effect of chemical situations on the half-life in electron capture.

The chemical situation changes the probability of a K-shell electron being available for electron capture. If the atom is ripped to its electrons, there are no electrons for a nucleus to capture.