HISTORY OF THE ATOM TIMELINE by Triston and Joseph

Democritus (430 B.C.)

450

Democritus descovered that all matter is made up of tinu particles called atoms. He believed you could break a peice of matterit couldnt be broken any further.
"Chemistry Project : The History Of The Atom." Chemistry Project : The History Of The Atom. N.p., n.d. Web. 26 Feb. 2014.

Aristotle (430 B.C.)

450

Argued with Democritus and said that matter is unifrom all the way through.
"Chemistry Project : The History Of The Atom." Chemistry Project : The History Of The Atom. N.p., n.d. Web. 26 Feb. 2014.

Dalton

Feb 28, 1803

Dalton proposed an atmoic theory. He perfomed experiments with various chemicals which showed that matter indeed seem to consist of elementary lumpy particles (atoms).
"A Brief History of Modern Atomic Theory." Chemistry Tutorial : History of Atomic Theory. N.p., n.d. Web. 25 Feb. 2014.

Thomson

Feb 28, 1904

Thomson infered that atoms cantain small, negatively charged particles embedded in a positively charged ball. He gathered his evidence through many expirements.
"History of Atoms." History of Atoms. N.p., n.d. Web. 26 Feb. 2014.

Rutherford

Feb 28, 1911

Rutherford disscovered that almost all the mass of the atom and all positive charges are located in the center of the atom, discoverd thrpugh gold-foil experiment.
"History of Atoms." History of Atoms. N.p., n.d. Web. 26 Feb. 2014.

Bohr

Feb 28, 1913

Bohr proposed the concept of energy levels to explain the spectrum of hydrogen.
"History of Atoms." History of Atoms. N.p., n.d. Web. 26 Feb. 2014.

Heisenberg and Schrodinger

Feb 28, 1926

These scientist discovered that electrons do not follow a fixed orbit but orbit occurs more in areas around the nucleus of the atom, found through Heisenburgs uncertainty principle.
"Chemistry Project : The History Of The Atom." Chemistry Project : The History Of The Atom. N.p., n.d. Web. 26 Feb. 2014.