Question

The charge to mass ratio of alpha particle approximately two the charge to mass ratio of proton is

Answer 1

The question is asked about the ratio between charge to mass ratio (e/m) of alpha particle and charge to mass ratio (e/m) of proton.
Alpha particle is nucleus of helium. They are having a +2 charge and atomic mass of 4u
So the e/m value will be 2/4=1/2
Proton is positive particle with atomic mass 1u. So the e/m ratio is 1/1=1
So the ratio between alpha particle and proton is 1/2 : 1 or 1:2