Proposed that all matter is made up of small individual particles called “atomos” which means invisible.

Formulated the atomic theory that all matter is composed of invisible particles as well as that atoms of the same element are identical. He also formulated the Law of Multiple Relationships.

Found that chemical compounds broke apart when an electric current was sent through, this meant that matter has an “electric nature.” He then developed the Laws of Electrolysis.

Stoney introduced the term electron as the “fundamental unit quantity of electricity.”

He was the discoverer of “anode rays,” which is a beam of positive ions. He is also given credit on discovering the proton.

Found that electrical charge is composed of negative charges particles called “electrons,” he also calculated the ratio between the electrons mass and charge. Thompson creates the “raisin cake” model of the atom.

Was known as the father of the “atomic nucleus,” he discovered that the nucleus was made up of protons and neutrons. Rutherford had also estimated the atoms size and concluded that the mass was concentrated in the nucleus.