Question

The particle with mass equal to $9.1\times {10}^{-31}kg$ and charge equal to $-1.6\times {10}^{-19}C$ is :

• A. $\beta$
• B. $\alpha$
• C. $\gamma$
• D. $X$

Answer 1

The correct option is A $\beta$

$\beta$ particles are electrons originating in the nucleus
Mass of an electron $=9.1\times {10}^{-31}kg$
Charge of an electron $=-1.6\times {10}^{-19}C$
$\alpha$-particle is a doubly ionized helium atom $\left({}_2^{4}He\right)$
Its mass is $4$ times mass of proton $=6.68\times {10}^{-27}kg$
Its charge is $2$ times the charge of proton $=3.2\times {10}^{-19}C$
$\gamma$-rays are not particles but radiations.
$X$-rays are not particles but EM radiations.