Question

Order of e/m ratio of proton, α-particle and electron is (please explain briefly)

Answer 1

Answer:

e/m for electron is 1/0 (as electron has negligible mass), for proton is 1/1, for neutron is 0/1, and for alpha particle is 2/4 or 1/2. Note that charge unit for e is -1, for proton is +1, for neutron is 0, and for alpha particle is +2.

Answer 2

Increasing order (lowest first) for the values of e/m (charge / mass) for electron (e), proton (p), neutron (n) and α-particle (α) is n,α,p,e

e/m for alpha particle = $\frac{2}{4} = 0.5$

e/m for proton = $\frac{1}{1} = 1$

e/m for electron =  $\frac{1}{\frac{1}{1850} } = 1850$

Note: e is the charge of the particle, m is the mass of a particle and the mass of an electron is  

α-particle < proton,< electron