Question

Answer the following question about α-particles.

What is its mass number and electric charge in a.m.u.?

Answer 1

An α-particle is a helium nucleus, $$ {}_2^4 \mathrm{He} $$. Its mass number is 4. Its electric charge is +2 in units of electronic charge, i.e., +3.2 × 10⁻¹⁹ C. Electric charge is not expressed in a.m.u.; its mass in atomic mass units is about 4 a.m.u.