During a negative beta decay
An atomic electron is ejected
An electron which is already present within the nucleus is ejected
A neutron in the nucleus decays emitting an electron
A part of the binding energy is converted into electron
Which can pass through $20 \,cm$ thickness of the steel
When $_{90}T{h^{228}}$ transforms to $_{83}B{i^{212}}$, then the number of the emitted $\alpha$- and $\alpha$- particles is, respectively
A radioactive element $_{90}{X^{238}}$ decay into $_{83}{Y^{222}}$. The number of $\beta - $ particles emitted are
In a radioactive decay chain, the initial nucleus is ${}_{90}^{232}Th$. At the end there are $6\,\,\alpha -$ particles and $4\,\,\beta -$ particles with are emitted. If the end nucleus is ${}_Z^AX\,,\,A$ and $Z$ are given by
$\gamma$-decay occurs when