What evidence caused Thomson to change Dalton's solid sphere model into the plum pudding model?

He found that the cathode ray elements have even negligible mass as compared to atoms. So he found that electrons are actually subatomic particles of an atom. That is why he suggested the plum pudding model.

Explanation:

He discerned that atoms contain charged particles, that he was known as electrons.

In chemist theoryThe indivisibility of associate, degree atom was proved wrong: associate degree atom is often any divided into protons, neutrons and electrons. but associate degree atom is that the smallest part icle that takes part in chemical reactions. in step with a chemist, the atoms of the same part are similar all told respects.

He found that the cathode ray elements have even negligible mass as compared to atoms. So he found that electrons are actually sub atomic particles of an atom. That is why he suggested plum pudding model.