-
500 BCE
The Alchemists
Discovered a substance that could change lesser metals to silver or gold. (proven false later) -
428 BCE
Plato
He invented the theorem of elements. -
400 BCE
Democritus
Discovered that all matter is made of atoms. -
Robert Boyle
Invented the theorem of atoms. -
Antone Lavoisier
Proved conservation of matter. -
Billiard Ball Model
Solid Sphere -
John Dalton
Discovered that compounds are elements together. -
Amadeo Avegadro
Proved that equal volume of gases at the same temperature have the same amount of molecules. -
James Chadwich
Proved that the Neutron existed. -
Dmitri Mendeleev
Created the Periodic table of elements. -
JJ Thompson
Determined charge of mass ratio of electrons. -
The Curies
Identified and studied many radioactive elements. -
Plum Pudding Model
Electrons surrounded by a positive mass. -
Albert Einstein
Discovered the Theory of Relativity -
Robert Millikan
Did the "Oil Drop" test. -
Ernest Rutherford
Discovered that the nucleus is positively charged. -
Neils Bohr
Discovered that outer orbit of electrons hold more than its inner orbit. -
Solar System Model
Nucleus orbited by electrons -
Henry Mosely
Proton corresponds to atomic number. -
Erwin Schrodinger
Mathematically showed how waves describe electrons in atoms. -
Electron Cloud Model
Nucleus surrounded by a cloud of electrons. -
Heisenberg
Created the Uncertainty Principle
