Electrons were discovered by

The correct option is "J.J Thompson." J.J. Thompson, a British physicist, discovered electrons in 1897. He conducted experiments with cathode ray tubes and observed that they produced a beam of negatively charged particles, which he called electrons. Thompson's discovery of electrons paved the way for further research into atomic structure and the development of modern electronics. The other options are not correct because they did not discover electrons. James Chadwick is known for discovering the neutron, Sir Isaac Newton is famous for his contributions to the fields of physics and mathematics, but he did not discover electrons, and there is no historical figure named Charles Newton who is associated with the discovery of electrons.