The nucleus produced due to $\alpha$-decay of the nucleus $_Z{X^A}$ is

Which of the following cannot be emitted by radioactive substances during their decay?

Give a brief explanation about radioactivity.

In a radioactive decay chain,the initial nucleus is ${}_{90}^{232}Th$. At the end,$6$ $\alpha$-particles and $4$ $\beta$-particles are emitted. If the final nucleus is ${}_{Z}^{A}X$,then $A$ and $Z$ are given by:

In the given reaction ${}_{Z}^{A}X \to {}_{Z+1}^{A}Y \to {}_{Z-1}^{A-4}K \to {}_{Z-1}^{A-4}K$,the radioactive radiations emitted in the sequence are:

During negative $\beta$-decay,which of the following processes occurs?