History of Atomic Structure

Democritus 460 B.C.

Jan 1, 1000

Father of modern science
Came up with first atomic theory
1) Everying is made of atoms
2) Atoms are indestructible
3) Atoms interact with other atoms mechanically
4) There is a finite amount of atoms always in motion.

Robert Boyle

Jan 1, 1661

Defied what elements are.
"Any substance that can't be broken down into two or more substances is an element"

Antoine Lavoisier

Jan 1, 1789

Law of conservation of mass

John Dalton

Jan 1, 1803

Atomic theroy
1. All mater made of atoms
2. Atoms are indivisible and indestructable
3. All atoms of a given element are identicle in mass and properties
4. Compounds formed by two or more different kinds of atoms
5. Chemical reaction is a reconfigurationn of atoms

Dmitri Mendeleev

Jan 1, 1869

1. fourmulated perodic table of chemical elements
2. Arranged by atomic weight
3. Sorted by properties

J.J. thomson

Jan 1, 1897

1. Discovered electron
2. Plum pudding model in 1904

Max Planck

Jan 1, 1900

1. Figured out radiation
2. Planck radation formula
3. Energy emited in diferent wave lenths

Eugen Goldstein

Jan 1, 1900

Proved the proton exists and is positively charged using cathode rays.

Robert Millikan

Jan 1, 1908

1. Discoved electrons charge independantly
2. Used the oil drop experiment
3. 1.592 x 10-19 charge of electrons

Ernesrt Rutherford

Jan 1, 1911

1. Gold foil experiment
2. Discovered the nucleus
3. Came up with rutherford model

Niels Bohr

Jan 1, 1913

1. Quantum theroy
2. Explained the inside of atoms
3. Atomic model
4. Electrons travel in seperate orbits

James Chadwick

Jan 1, 1932

1. Proved nuetrons existance
2. Atom number determed by protons

Erwin Shrodinger

Jan 1, 1940

1. Nobel prize in physics
2. used math to describe the likely-hood of finding an electron in a certan position
3. "Electron cloud"