Atomic Theory timeline

Democritus (460-370 B.C.)

• proposed that all matter is made of atoms
• Atoms are uncuttable
• atoms have been and always will be in motion
• known as laughing philosopher 
• lived in Abdera, Thrace 

John Dalton (1766-1844)

• Atoms are invisible and indestructable
• compounds are formed from combining two or more different atoms
• atoms with the same elements are have the same mass and properties
• Born in Eaglesfield, England

Ernest Rutherford (1871-1937)

• hypothesized nuclear structure of atom
• identified Alpha particles as helium nuclei 
• Born on a farm in New Zealand

JJ Thompson (1856-1940)

• Constructed deflection techniques to measure the charge to mass ratio
• discovered neon was composed of two different kinds of atoms
• proved that isotopes existed in a stable element
• born in Cheetham Hill, England

Neils Bohr (1885-1965)

• made the atomic structure which became the basis of the quantum theory
• Also came up with the Shell model of the atom
• born in Copenhagen, Denmark

Werner Heisenberg ( 1901-1976 )

• Discovery of the nucleus
• developed model of proton and neutron interaction (strong force)
• Embarked on a research program to create a quantum field theory
• born in Würzburg, Germany
• Part of the modern day theory

Erwin Schrödinger (1887-1961)

• used mathematical equations to experiment 
• developed way to determine likelyhood of an electron in a certain position
• developed quantum mechanical model of the atom
• born in Vienna, Austria
• Other person to created modern atomic theory