History of the Atom Timeline by Tyler George

Democritus (500 BC)

450

Democritus generally said that you can cut an item in half until "it cant be cut in half anymore". He also said that the smallest parts were "atomos" and came in different shapes. Hudak, Madison. "Atomic Model Timeline." Prezi.com. Prezi Inc., n.d. Web. 27 Feb. 2014.
DeWitt, Tyler. "Models of the Atom Timeline." YouTube. YouTube, 06 Dec. 2012. Web. 27 Feb. 2014.

Aristotle (350 BC)

450

Aristotle believed that different things were made of "different amounts of the elements earth, fire, water, and air". This idea put Democritus' idea out of the picture for a while. "Science 122 Program 7: The Golden Age." Science 122 Program 7: The Golden Age. N.p., n.d. Web. 27 Feb. 2014. DeWitt, Tyler. "Models of the Atom Timeline." YouTube. YouTube, 06 Dec. 2012. Web. 27 Feb. 2014.

Dalton

Feb 28, 1808

Dalton did an experiment in which he said that atoms linked together to form different elements. This idea was doubted for many years until others started experimenting for themselves. "Dalton Atomic Theory." Dalton Atomic Theory. N.p., n.d. Web. 25 Feb. 2014.

Thompson

Feb 28, 1904

Thompson built on Dalton's works and created the plum pudding model. He proposed that atoms are positively charged with negative electrons floating inside. "Rutherford Model of the Atom." , Gold Foil Experiment. N.p., n.d. Web. 27 Feb. 2014.
DeWitt, Tyler. "Models of the Atom Timeline." YouTube. YouTube, 06 Dec. 2012. Web. 27 Feb. 2014.

Rutherford

Feb 28, 1911

Rutherford built on Thompson's model in doing the Gold Foil Experiment, saying that the nucleus was positive, and the electrons orbitied it instead of having a solid orb of positive and negative particles. "It's a Question of Physics: What Is an Atom?" What Is an Atom? N.p., n.d. Web. 27 Feb. 2014.
DeWitt, Tyler. "Models of the Atom Timeline." YouTube. YouTube, 06 Dec. 2012. Web. 27 Feb. 2014.
"Rutherford Model of the Atom." , Gold Foil Experiment. N.p., n.d. Web. 27 Feb. 2014.

Bohr

Feb 28, 1913

Bohr said that electrons are in different orbits around the nucleus, like planets orbit around the sun. This idea was widely accepted.

Heisenberg and Schrodinger

Feb 28, 1920

Heisenberg and Schrodenger proposed that electrons were like flies that rapidly moved around in layers. They found that you can either know the location or the speed of an electron, but not both. DeWitt, Tyler. "Models of the Atom Timeline." YouTube. YouTube, 06 Dec. 2012. Web. 27 Feb. 2014.
Malham, Simon. "Simon Malham Home Page." Simon Malham Home Page. N.p., n.d. Web. 27 Feb. 2014.