What subatomic particles compose the mass of an atom?

Answer 1

All subatomic particles have mass, bar the photon and the gluon. The masses of some of the most well-known are as follows:

Electron: 0.511 MeV/c^2

Proton: 938.272 MeV/c^2

Neutron: 939.565 MeV/c^2

Electron Neutrino: ~2.2 MeV/c^2

N.B: All masses have been expressed using Einstein's mass-energy equivalence (E=m.c^2); the mass is thus expressed in terms of energy/c^2 as the masses (in kg) would be extremely small.

Answer 2

The bulk of an atom's mass comes from its nucleus. Since protons and neutrons reside in the nucleus, they then must provide most of the mass. The electrons outside of the nucleus do also have mass, but it is much, much less than that of protons or neutrons.

Answer 3

The mass of an atom= the number of protons + the number of neutrons

Answer 4

the sum of protons and neutron.but the contribution of the electron is negligible compared to that of proton and neutron

Answer 5

Protons and neutrons are subatomic particles in mass. The nucleus determines the Atomic Mass.

Answer 6

Protns and neutrons.