Sub Atomic Particles

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.

Electron:

• Discovered by J.J. Thomson.
• It is defined as the subatomic particle with unit negative charge and mass which is equal to 1/1837^th of that of hydrogen gas.
• Charge of electron: 1.6 × 10^-19 column
• Mass of electron: 9.1× 10^-31 kg

Proton:

• 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

Neutron:

• 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