The number of $\alpha$ and $\beta^-$ particles emitted during the radioactive decay chain starting from ${}_{88}^{226}Ra$ and ending at ${}_{82}^{206}Pb$ is:

Some radioactive nucleus may emit

Consider the following radioactive decay process:
${ }_{84}^{218} A \stackrel{\alpha}{\longrightarrow} A_1 \stackrel{\beta^{-}}{\longrightarrow} A_2 \stackrel{\gamma}{\longrightarrow} A_3 \stackrel{\alpha}{\longrightarrow} A_4 \stackrel{\beta^{+}}{\longrightarrow} A_5 \stackrel{\gamma}{\longrightarrow} A_6$
The mass number and the atomic number of $A_6$ are given by:

Alpha rays emitted from a radioactive substance are:

Which one of the following cannot emit $\gamma$-radiation and why? $(i)$ Excited nucleus,(ii) Excited electron.

The $Q$-value of the decay ${ }_{11}^{22} Na \rightarrow{ }_{10}^{22} Ne + e ^{+}+v$ is