The electron was discovered by Joseph John Thomson. J.J. Thomson discovered the electron in 1897 through his experiments with cathode ray tubes, determining that cathode rays were composed of negatively charged particles much smaller than atoms. Michael Faraday contributed significantly to electromagnetism and electrochemistry. Henry Cavendish discovered hydrogen and determined the composition of water. Ernest Rutherford conducted the gold foil experiment leading to the discovery of the atomic nucleus and later discovered the proton.