Radioactivity is a/an ...... process.

What happens to the mass number and atomic number of an element when it emits $\gamma$-radiation?

In the radioactive disintegration series,for the process $_{92}^{238}U \xrightarrow{\alpha} X \xrightarrow{\beta^-} {}_{Z}^{A}Y$,the values of $Z$ and $A$ respectively are:

Identify the particle $x$ in the following reaction: ${}_3^7Li(p, x){}_4Be^8$,where $p$ is a proton.

Consider the decay of a free neutron at rest: $n \rightarrow p + e^-$. Show that the two-body decay of this type must necessarily give an electron of fixed energy and,therefore,cannot account for the observed continuous energy distribution in the $\beta$-decay of a neutron or a nucleus.

$A$ nucleus with mass number $184$ initially at rest emits an $\alpha$-particle. If the $Q$ value of the reaction is $5.5\, \text{MeV}$,calculate the kinetic energy of the $\alpha$-particle in $\text{MeV}$.