The modern treatment method $P.E.T.$ is based on:

$A$ radioactive element forms its own isotope after $3$ consecutive disintegrations. The particles emitted are

In the nuclear reaction $_{85}X^{297} \to Y + 4\alpha$,$Y$ is:

When a neutron is disintegrated to give a $\beta$-particle,which of the following is also emitted?

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 $y$.

Which of the following rays are not electromagnetic waves?