Question

Ratio of e/m of Alpha particle and proton is

Answer 1

2:1 is the ratio of alpha particle and proton

Answer 2

Alpha particle is a helium nucleus which consists two protons and two electrons. It has +2 charge and the mass of four protons. So the alpha particle has the least E/M because of its large mass.You can see that its E/M is equal to 1/2 time E/M of a proton.