Answer:
Electron
Step-by-step explanation:
Thomson performed experiment with cathode ray tube and showed that in all the atoms there are some tiny negatively charged subatomic particles, these are named electrons. As he was knowing that atoms are neutral, he proposed a model of atom based on his experiment and said that in atoms negatively charged particles (electrons) are embedded within a positively charged "soup". This model was called the plum pudding model of the atom.