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, identify its exchange boson, and explain why this interaction is uniquely capable of causing 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 explain how they could be detected and distinguished from the products of electron capture decay.
50 exam-style questions on AQA A Level Physics Particles, covering Constituents of the atom, Stable and unstable nuclei, Particles, antiparticles and photons, Particle interactions, Classification of particles, Quarks and antiquarks, and Applications of conservation laws. Each one has a worked solution and a mark scheme showing where the marks go.