Who discovered electron?

Answer: The correct answer is J.J. Thomson. 

Electrons were discovered by J.J Thomson after many experiments involving cathode rays. He demonstrated the ratio of mass to electric charge of cathode rays. 

He confirmed that cathode rays are fundamental particles that are negatively charged; these cathode rays became known as electrons. It is one of those subatomic particles. 

• Charge: Robert Millikan, through oil drop experiments, found the value of the electronic charge.
  • Electrons can abbreviate as e- and have a negative charge that is equal in magnitude to the positive charge of the protons as the atoms are neutral.
  • The charge on an electron is 1.6020*10^-19 C, which is considerably less than that of a proton or neutron.
• Mass: The mass of an electron is 9.1*10^-31 kg.
• Location: Thomson and Rutherford tried to predict the location of electrons but it was Niels Bohr who postulated it most correctly.
  • Electrons revolve around the nucleus of an atom in a circular orbit having fixed energy. After gaining/losing energy, an electron can move to a different orbit of that energy level.
  • Later, after the discovery of quantum mechanics, it was postulated that electrons move randomly around the nucleus and the maximum probability of its finding is called orbital.
  • Orbitals can be of various shapes - spherical, dumbbell, double dumbbell, etc.