An isotope of argon, 1837Ar{}^{37}_{18}\text{Ar}1837Ar, decays into an isotope of chlorine (Cl) by electron capture.
Complete the equation for this decay by filling in the blanks: 1837Ar+−10e→‾Cl+‾{}^{37}_{18}\text{Ar} + {}^{0}_{-1}\text{e} \rightarrow \underline{\quad}\text{Cl} + \underline{\quad}1837Ar+−10e→Cl+
Name the fundamental interaction responsible for this decay and explain why it is the only interaction capable of this change.
After the decay, the chlorine nucleus is in an excited state. It returns to its ground state by emitting a single gamma photon with an energy of 0.320 MeV0.320 \text{ MeV}0.320 MeV. Calculate the wavelength of this photon.
Another isotope, argon-39 (1839Ar{}^{39}_{18}\text{Ar}1839Ar), decays by a different process to form potassium-39 (1939K{}^{39}_{19}\text{K}1939K). Suggest what particles are emitted in this second process and how they could be detected to distinguish it from the electron capture decay of argon-37.
