Radioactive carbon dating was discovered by

The element with atomic number $84$ and mass number $218$ changes to another element with atomic number $84$ and mass number $214$. The number of $\alpha$ and $\beta$-particles emitted are respectively:

Which statement is incorrect?

If $_{92}U^{236}$ nucleus emits one $\alpha$-particle,the remaining nucleus will have

$A$ radioisotope will not emit

$_{11}^{23}Na$ is the more stable isotope of $Na$. Find out the process by which $_{11}^{24}Na$ can undergo radioactive decay.