What is the mass of an atom that contains two positively charged nuclides, and two neutrally charged nuclides? What is the atom?

1 Answer
Jul 21, 2017


Well, the conventional helium NUCLEUS comprises 4 massive particles.....


Atomic mass is to a very good first approx. NUCLEAR mass, i.e. the number of massive nuclear particles. The helium nucleus has 2 protons, 2 positively charged, massive particles, #Z=2#, and this is what defines the nucleus as helium. The common helium isotope also contains 2 neutrons to give #""^4He#. Capisce?