Radioactivity of the neptunium series stops when it is converted to:

$_{92}U^{238}$ emits $8$ $\alpha$-particles and $6$ $\beta$-particles. The neutron/proton ratio in the product nucleus is

Who observed that when the nucleus of a uranium atom was bombarded with fast-moving neutrons,it became so unstable that it immediately broke into two nuclei of nearly equal mass,besides other fragments?

The number of neutrons in the parent nucleus which gives $N^{14}$ on $\beta$-emission and the parent nucleus is

Which among the following minerals contains a radioactive element?

In the radioactive disintegration series ${}_{90}^{232}Th \rightarrow {}_{82}^{208}Pb$ involving $\alpha$ and $\beta$ decay,the total number of $\alpha$ and $\beta$ particles emitted are: