Question

The three types of radioactivity in increasing order of penetrating power are?

• A. beta, alpha, gamma
• B. gamma, beta, alpha
• C. alpha, beta, gamma
• D. alpha, gamma, beta

Answer 1

The correct option is C

alpha, beta, gamma

$\alpha$-rays have the least penetrating power, they can penetrate a 0.01 mm thick $Al$ foil.

$\beta$-rays have more penetrating power than $alpha$-rays, they can penetrate a 0.2 mm $Al$ foil.

$\gamma$-rays have the highest penetrating power, they can penetrate a 1000 mm thick $Al$ sheet.