Proposed that all matter is made up of small individual particles called “atomos” which means invisible.
Democritus a Greek philosopher
0420 BC
John Dalton
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.
John Dalton
1803
Micheal Faraday
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.
Micheal Faraday
1832
George Johnstone Stoney
Stoney introduced the term electron as the “fundamental unit quantity of electricity.”
George Johnstone Stoney
1874
Eugen Goldstein
He was the discoverer of “anode rays,” which is a beam of positive ions. He is also given credit on discovering the proton.
Eugen Goldstein (1850-1930)
1886
JJ. Thompson
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.
JJ. Thompson (1856-1940)
1897
Ernest Rutherford
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.