In the late 1800s, experiments using cathode ray tubes led to the discovery of the
(1) electron (3) positron
(2) neutron (4) proton

This experiment showed whomever it was (Rutherford? I can't remember exactly), that light is made up of something that when a magnet is near it, the cathode ray would bend either towards the north end of the magnet, or repel the negative end. This gave the scientist the idea that there was a negatively charged particle, leading to the discovery of: (1) The electron.