Physics 9702 · AS & A Level · Fundamental particles
Fundamental particles — practice question
A nucleus of element $X$ undergoes decay by releasing a $\beta^+$ particle, forming potassium-39 $\left(^{39}_{19}\text{K}\right)$ and a neutrino. The decay is written as $^{Q}_{S}X \rightarrow ^{39}_{19}\text{K} + ^{P}_{R}\beta^+ + ^{0}_{0}\nu$.
(a(i))[2]
State the value represented by each letter listed here: $P$, $Q$, $R$, $S$.
(a(ii))[1]
State which interaction (force) causes $\beta^+$ decay.
(b)[2]
A hadron contains three identical quarks and carries charge $+2e$, where $e$ is the elementary charge. Determine a possible quark type (flavour). Explain your working.
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “$Q = 39$ and $P = 0$” …