In a nuclear breeder reactor, a uranium-238 (92238U^{238}_{92}\text{U}92238U) nucleus absorbs a neutron (n\text{n}n) to begin a sequence of reactions that eventually yields a plutonium isotope, Z\text{Z}Z.
U−238+n→X \text{U}-238 + \text{n} \rightarrow \text{X} U−238+n→X X→Y+β−+νˉe \text{X} \rightarrow \text{Y} + \beta^- + \bar{\nu}_{\text{e}} X→Y+β−+νˉe Y→Z+β−+νˉe \text{Y} \rightarrow \text{Z} + \beta^- + \bar{\nu}_{\text{e}} Y→Z+β−+νˉeHow many neutrons does the resulting nucleus Z\text{Z}Z contain?
144144144
145145145
146146146
239239239
128 exam-style questions on AQA A Level Physics Radioactivity (A-level only), covering Rutherford scattering (A-level only), $\alpha$ , $\beta$ and $\gamma$ radiation (A-level only), Radioactive decay (A-level only), Nuclear instability (A-level only), Nuclear radius (A-level only), Mass and energy (A-level only), Induced fission (A-level only), and Safety aspects (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.