What are the atoms subatomic particles?

The proton, neutron and electron are the three subatomic particles.

Protons and neutrons are formed from quarks and gluons.

The proton and neutron carry a (nearly) identical mass.

m_p = 1.673 * 10^-27 kilograms

m_n = 1.675 * 10^-27 kilograms

while the electron is considerably smaller and much less massive.

m_e = 9.110 * 10^-31 kilograms

For those unfamiliar with scientific notation, those numbers are:

m_p = .000000000000000000000000001673 kg

m_n = .000000000000000000000000001675 kg

m_e = .000000000000000000000000000000911 kg

Protons carry a positive electric charge while electrons carry an equal and

opposite negative charge. Neutrons are electrically neutral.