Question

The radiation with the highest ionization power is:

• A. Alpha
• B. Beta
• C. Gamma
• D. X

Answer 1

The correct option is A Alpha

Alpha particles have the highest ionisation power than the other two types of radiation owing to the fact that an $\alpha$-particle is doubly ionised helium nucleus, i.e. ${\text{He}}^{\text{2+}}$. Beta particles are simply electrons (${\text{e}}^{\text{-1}}$), and gamma rays are uncharged EM radiation. Therefore, out of the three, $\alpha$-rays have the most electric charge and are the most massive. Hence, when they are passed through a substance, they tend to ionise the substance (by attracting and stripping off the electrons from it) than $\beta$ and $\gamma$ radiation. X-rays are also a part of EM radiation, but still cannot ionise as powerful as $\alpha$-rays.