During a $\beta$-decay,the mass of the atomic nucleus

$A$ device used for the measurement of radioactivity is

Consider the radioactive disintegration ${}_{82}A^{210}$ $\rightarrow B$ $\rightarrow C$ $\rightarrow {}_{82}D^{206}$. The sequence of emission can be

$A$ radioactive nucleus will not emit

$A$ radioactive nuclide $X$ decays at the rate of $1.00 \times 10^5 \ disintegration \ s^{-1} \ g^{-1}$. Radium decays at the rate of $3.70 \times 10^{10} \ disintegration \ s^{-1} \ g^{-1}$. The activity of $X$ in millicuries $g^{-1}$ $(mCi \ g^{-1})$ is

Which of the following processes does not occur via $\alpha$-decay?