1) Subatomic particles. Atoms are made up of smaller parts called subatomic particles. Proton, neutron, and electron are some of them.
Electron: 9.11*10^-31 kg.
Proton: 1.672 18*10^-27 kg.
Neutron: 1.674 93*10^27 kg.
The lightest subatomic particle is the electron, then comes the protons, and finally the electron.
