Thomson's Model of Atom

Dalton believed that an atom is indivisible and indestructible.

But his theory failed with the discovery of fundamental particles within an atom.

So, it became necessary to know the way the fundamental particles are arranged within an atom.

J. J. Thomson was one of the first to propose the structure of an atom.

He realised that for an atom to be neutral, it should have an equal number of positive and negative charges.

So, he proposed that an atom consists of a positively charged soup or cloud, where the electrons are suspended.

His model of the atom is called Thomson's atomic model.

Many scientists called it the watermelon model as it reminded them of watermelons.

This brings us to the postulates of Thomson's model of an atom.

Firstly, an atom consists of a positively charged cloud with electrons embedded in it.

Secondly, the negative and positive charges are equal in magnitude. So, the atom as a whole is electrically neutral.

Lastly, the mass of an atom is uniformly distributed throughout.

Thomson's model of an atom however was not perfect.

Thomson could not properly define what the positively charged part of the atom really contained.

He also did not clearly explain whether the electrons in the positively charged sphere are fixed or move about randomly

Revision

J.J. Thomson proposed that an atom consists of a positively charged soup or cloud, where the electrons are suspended.

Many scientists called it the watermelon model as it reminded them of watermelons.

Thomson however could not properly define what the positively charged part of the atom really contained.

He also did not clearly explain whether the electrons in the positively charged sphere are fixed or move about randomly

The End