Question

Describe Thomson's plum pudding model. Which subatomic particle was not present in this model of the atom.

Answer 1

The main two points of Thomson's model of an atom are as follows:

1. An atom is made up of a uniform positive charge and negatively charged electrons contained in it.
2. An atom is neutral because its positive & negative charges are of equal magnitude.

• The neutron was discovered by James Chadwick in 1931.
• Thus neutron is a subatomic particle that is not present in this model of an atom given by J.J.Thomson in 1903.