Question

The correct decreasing order of charge/mass ratio among the following is:

• A. $e^{-},H^{+},\alpha$
• B. $H^{+},\alpha ,e^{-}$
• C. $H^{+},e^{-},\alpha$
• D. $\alpha ,H^{+},e^{-}$

Answer 1

The correct option is A $e^{-},H^{+},\alpha$

The $\frac{e}{m}$ (charge/mass) ratio increases with increasing charge and decreasing mass.
The electron has the smallest mass, followed by the proton and then the alpha particle.
The alpha particle has the largest charge (+2), the proton (+1) and the electron (-1) have the same magnitude of charge.