Physics 9702 · AS & A Level · Atoms, nuclei and radiation
Atoms, nuclei and radiation — practice question
An isolated nucleus $X$, initially at rest, decays by emitting an $\alpha$-particle and produces nucleus $Y$. Nucleus $Y$ and nucleus $Z$ are isotopes of the same element.
(a(i))[1]
Using the proton numbers of the two nuclei, state and explain whether the charge of nucleus $Y$ is less than, greater than, or equal to the charge of nucleus $Z$.
(a(ii))[2]
Using the proton numbers in each nucleus, state and explain whether the charge of nucleus $Y$ is less than, greater than, or equal to the charge of nucleus $X$.
(b)[2]
Use conservation of momentum to explain why nucleus $Y$ cannot be at rest immediately after nucleus $X$ decays.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Y and Z contain the same number of protons, so they have the same charge” …