-
350
Aristotle
He gave his theory that atoms we made of fire, water, earth, and air -
400
Democritus
Said that "atoms are the basic buldings blocks of matter" -
Dalton
Atomic Theory -
Mendeleev
He arranged the periodic table by the atomic mass for the first time -
JJ Thomson
He discovered electrons and explainedhis thoughts in
Treatise on the Motion of Vortex Rings -
Crooke
Invented the Crooke's Tube -
Rutherford
He reported that alpha exsisted and beta rays in uranium radiation and indicated some of their properties. -
Bohr
Said that electrons travel around the "shell" of an atom
