(a)[2]
Determine the proton number and the neutron number of nucleus X.
(b)[2]
Calculate how many plutonium-238 nuclei must decay during a time of $1.0\,\text{s}$ in order to produce a power of $0.15\,\text{W}$.
Physics 9702 · AS & A Level · Atoms, nuclei and radiation
Atoms, nuclei and radiation — practice question
A nucleus of plutonium-238 ($^{238}_{94}\text{Pu}$) undergoes decay by emitting an $\alpha$-particle, forming a new nucleus X and releasing $5.6\,\text{MeV}$ of energy. The decay can be written as $^{238}_{94}\text{Pu} \rightarrow X + \alpha + 5.6\,\text{MeV}$.