$A$ free neutron decays into a proton, an electron and

Beta rays emitted by a radioactive material are

In the emission of $\gamma$-rays from a nucleus:

In the uranium radioactive series,the initial nucleus is $_{92}U^{238}$ and the final nucleus is $_{82}Pb^{206}$. When the uranium nucleus decays to lead,the number of $\alpha$-particles emitted is $x$ and the number of $\beta$-particles emitted is $y$. Find $x$ and $y$.

For the radioactive nuclei that undergo either $\alpha$ or $\beta$ decay, which one of the following cannot occur?

$A$ nucleus $_Z{X^A}$ emits $3 \alpha$-particles and $5 \beta$-particles. The ratio of total neutrons to protons in the final nucleus is: