In 1903, physicist Joseph John Thomson proposed a new atomic model, based on cathode ray experiments, which he called electrons.
For Thomson, the atom was a sphere of positive electric charge "filled" with negatively charged electrons.
The model became known as "raisin pudding". This model overturns the idea that the atom is indivisible and introduces the electrical nature of matter.
Thomson's model explains some phenomena, such as electric current, friction electrification, ion formation and gas discharge.