Those particles which are present within the atoms of an element are called sub-atomic particles. Examples: proton, neutron, electron etc. There are more than 35 sub atomic particles in an atom. Out of these subatomic particles proton, neutron and electron are called fundamental particles.
- Discovered by J.J. Thomson.
- It is defined as the subatomic particle with unit negative charge and mass which is equal to 1/1837th of that of hydrogen gas.
- Charge of electron: 1.6 × 10-19 column
- Mass of electron: 9.1× 10-31 kg
- Discovered by E. Goldstein.
- Proton can be defined as the sub-atomic particle having unit positive charge and mass equal to 1 atom of hydrogen.
- Charge of Proton: 1.6 × 10-19 column
Mass of Proton: 1.6 × 10-27Kg
- Discovered by Chadwick.
- When a beryllium atom is bombarded with alpha particles, a highly penetrating particle with zero charge is obtained called neutron.
- Neutron is a sub atomic particle having no charge. It’s mass is nearly equal to that of one atom of hydrogen.
- Mass of neutron = 1.67 × 10-27Kg
- Charge of neutron = 0