History of the Atom Tre Hendricks and Dylan Honore

Aristotle B.C.E

340

Aristotle disbelieved in the theory of atoms. Instead he believed in the four elements: air, water, fire and earth.

Democritus B.C.E

460

Democritus' theory concluded that everything is acomposed of atoms and "physically, but geometrically, indivisible".
He used mathematical models or drawings distinguished by size, shape, and by their parts.

Dalton

Feb 28, 1803

"1) Elements are made of extremely small particles called atoms
2) Atoms of a given element are identical in size, mass, and other properties
3) Atoms cannot be subdivided, created, or destroyed
4) Atoms of different elements combine in simple whole-number ratios to form chemical compounds
5) In chemical reactions, atoms are combined, separated, or rearranged"

Thomson

Feb 28, 1897

Discovered that electrons were neighboring the nucleus. Did not discover electrons were in an orbital pattern.
He found it by experimenting with electricity in tubes.
He then created a model for atoms called "The Plum Pudding Model"

Rutherford

Feb 28, 1911

Theorized atoms were made up like the solar systems. Also said the heavy part in the middle is called a neucleus in the middle of each atom.
Created a science experiment called "The Gold Foil Experiment"

Bohr

Feb 28, 1913

Added to Rutherford's theory how atoms give off radiation. Consisted of extremely small positive charged nucleus.
Performed numerous experipents on the hydrogen element.

Heisenberg and Schrodinger

Mar 3, 1925

Subatomic particles, the small parts create atoms. Doing more research Schrodinger created the function for the quantum theory.
They made their discovery through a series of experiments at quantum level.