${U^{238}}$ decays into $T{h^{234}}$ by the emission of an $\alpha - $ particle. There follows a chain of further radioactive decays, either by $\alpha - $ decay or by $\beta $ - decay. Eventually a stable nuclide is reached and after that, no further radioactive decay is possible. Which of the following stable nuclides is the and product of the ${U^{238}}$ radioactive decay chain

A deutron is bombarded on $_8{O^{16}}$ nucleus and $\alpha$-particle is emitted. The product nucleus is

In gamma ray emission from a nucleus

When a radioactive substance emits an $\alpha$- particle, its position in the periodic table is lowered by

On the bombardment of neutron with Boron. $\alpha$-particle is emitted and product nuclei formed is

In the following nuclear rection, $D \stackrel{\alpha}{\longrightarrow} D _{1} \stackrel{\beta-}{\longrightarrow} D _{2} \stackrel{\alpha}{\longrightarrow} D _{3} \stackrel{\gamma}{\longrightarrow} D _{4}$ Mass number of $D$ is $182$ and atomic number is $74$ . Mass number and atomic number of $D _{4}$ respectively will be