1. J.J. Thomson’s atom model with the help of a diagram:
- Thomson proposed that the shape of an atom resembles a sphere having a radius of the order of 10 m.
- The positively charged particles are uniformly distributed with electrons arranged in such a manner that the atom is electrically neutral.
- Thomson’s atom model was also called as the plum pudding model or the watermelon model.
- The embedded electrons resembled the seed of watermelon while the watermelon’s red mass represented the positive charge distribution.
- The plum pudding atomic theory assumed that the mass of an atom is uniformly distributed all over the atom.
2. Limitations of Thomson’s Atom model:
- Thomson’s model failed to explain how the positively charged sphere is shielded from the negatively charged electrons without getting neutralized.
- This theory explains only about the protons and electrons and failed to explain the presence of neutral particle neutron.
