During the emission of a $\beta$-particle,what happens to the nucleus?

Which metal is used in radiation shielding?

Who developed the study of radioactivity?

In the radioactive decay of $X$ into $Y$ as shown below,what is the value of $_Z{Y^m}$?
$_{6}{X^{14}} \xrightarrow{-3\beta} {_{Z}}{Y^{m}}$

In radioactive decay,which one of the following moves the fastest?

An atom has a mass number of $232$ and an atomic number of $90$. How many $\alpha$-particles should it emit after the emission of two $\beta$-particles,so that the resulting atom has a mass number of $212$ and an atomic number of $82$?