History of the Atom

Democritus BC

400

He believed atoms are consisted of invisible particles he called atoms. They are indestrucible, solid, homogenous, and vary in size shape mass position and arrangement.
"Democritus." The-History-of-the-Atom -. N.p., n.d. Web. 26 Feb. 2014.

Dalton

Mar 5, 1803

He believed everything is made up of atoms. he made the first chart of atomic weights.
"John Dalton Biography." Bio.com. A&E Networks Television, n.d. Web. 28 Feb. 2014.

Thomas

Mar 5, 1897

He believed atoms are consisted of a sphere of positive charge with negatively charged electrons embedded in it.
"Joseph John Thomson." Homepage of the Chemical Heritage Foundation. Chemical Heritage Foundation, n.d. Web. 25 Feb. 2014.

Rutherford

Mar 5, 1911

He believed the atom has a central positive nucleus surrounded by negitive orbiting electrons.
"Rutherford - Atomic Theory." Rutherford - Atomic Theory. N.p., n.d. Web. 26 Feb. 2014.

Bohr

Mar 5, 1913

Electrons orbit the nucleus without losing energy, move only in fixed orbits of specfic energies, and electrons with low energy would move closer to the nucleus while ones with higher energy will move futher away.
"HISTORY OF THE ATOM FROM DEMOCRITUS TO BOHR AND SCHRÖDINGER." HISTORY OF THE ATOM FROM DEMOCRITUS TO BOHR AND SCHRÖDINGER. N.p., n.d. Web. 25 Feb. 2014.

Heisenburg and Schrodinger

Mar 5, 1925

Schrodinger described the movement of electrons with an question, made an electron "cloud" model, and believed electrons moved in waves. Heisenburg used a microscrope to measure the momentum from an electron.
Beyler, Richard. "Werner Heisenberg (German Physicist and Philosopher)." Encyclopedia Britannica Online. Encyclopedia Britannica, n.d. Web. 25 Feb. 2014.

Aristotle BC

Mar 2, 2022

He didn't believe in the atomic theory. He believed that all materials on Earth were made up of earth, wind, fire, and water.
"History of Atoms." History of Atoms. N.p., n.d. Web. 26 Feb. 2014.