From the Old Atomic Theory to the Modern Day Atomic Theory

Democritus

400

He thought mater made particles. Particles could not be cut. He calld it an atom. He thought atoms were indivisble, Atom comes from the word atomos. Atomos is greek for indivisible.

John Dalton

Oct 2, 1780

He thought they were solid sphere. All substances are made of atoms. Atoms of the same element are exactly alike. Atoms join with other atoms.

Thomson

Oct 2, 1897

Small Atoms are inside of small particles so they can join together.

Ernest Rutherford

Oct 2, 1909

Atoms are soft bllobs of matter. Atoms can pass right throught gold on a straight line. And he cslled his model Rutherfords model.

Bohr

Oct 3, 1913

He wascalled the Father of Quantam theory because he proposed that electrons move around the nucleus in certains paths or energy levels. Bohr made up the "Bohr Planetary Model."

Aston

Feb 2, 1919

Discovered the existence of isotopes through the use of a mass spectrograph.

Ernest Schrodinger/Werner Heisen

Dec 6, 1926

They made the modern day atomc theory and there model was the electron clouds theory. Schrodinger identified the electron cloud as the propable location of moving particles.

James Chadwick

Oct 3, 1932

Chadwick proved the existance of a neutron. He also discoverd a particle within the nucleus that has a mass similar to that of a proton. And he didnt have a model.

Aristotle

Mar 2, 2022

He disagreed with Democritus's ideas. He thought could never end up with a paricle that could be cut. For a long time most people thought he was right because of the strong influence he had on them.