Which particle is j. j. thomson credited with discovering? electron neutron proton photon

Electron

Explanation:

Thomson discovered the electron performing a series of experiments with cathode ray tubes. He measured the charge and mass of the cathode rays when they were deviated by a magnetic field, finding a particle lighter and with more charge than that of the hydrogen ion. With this, he concluded that the atoms were divisible and imagine the atom like a sea full of positive charges with negative charge particles within it. His atomic model is also known as the plum pudding model.

whats the meaning of /

catya that's not even a b or c