How were the results of discharge tube experiments interpreted by J. J. Thomson in terms of model of an atom?

The identification of cathode rays constituting charged electrons led to the conclusion that
(i) Electrons are present in an atom.
(ii) These electrons are embedded in a sphere of positive charge.
(iii) The comparison of e/m values for electron and H⁺, Na⁺ or other ions showed that the remaining part should be 2000 times heavier than the electron.
On this basis J.J. Thomson gave a model of the atom in which electrons and mass were distributed throughout the full size of atom. The size of the atom was estimated to be about 10^-10 m. fig. gives model of three atoms containing one, two and three electrons. This model was considered to be very unstable.

Thomson proposed the model of an atom to be similar to that of watermelon. the positive charge in the atom is spread all over like the red edible part of the watermelon, while the electrons are studded in the positively charged sphere, like the seeds in the watermelon.