Question

The e/m ratio is minimum for :-​

Answer 1

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. The mass unit (amu) for e is almost 0, fro p is 1, for neutron is 1, and for alpha particles is 4.