History of the Atom by Keshaun Brown

Democritus

400

Everything is made of particles.
Atoms are physically, not geometrically invisble.
Between atoms lie empty space.
Atoms are indestructible, have been and always will be in motion.
Used analoges of his senses.
Looks like the substance it caomes from.

History Of The Atomic Model

Period: 400 to Mar 8, 1926

Dalton

Mar 8, 1803

All matter is made of atoms.
Atoms are indivisble, and indestructible.
All elements of given elements are identical in mass and properties.
Compounds are formed by a combination of two or more different kind of atom.
A chemical reaction is a rearrangement of atoms.
Used a chemical reaction
Looked like a atom and two molecules.

Thomson

Mar 8, 1897

He added and changed electrons.
Used the Plum Pudding Model and the High Vaccum Cathoderay
It looked like a sphere of positive matter; in which electrons are positioned by electrstatic forces.

Rutherford

Mar 8, 1909

Atom consist of nucleus.
Contains whole positive charge and whole atom mass.
Electron rotate on orbits.
Used the Gold Foil Experiment
Looked liked a planetary.
Nuclues in middle.
Electronms circling.

Bohr

Mar 8, 1913

Electrons move in orbits of fixed size and energy.
Electron energy depend on size of the orbit and lower for smaller orbits.
Used a mathemartical model.
Quantums Physics
Plannacks Constant
Present Models
Bohr Model

Heisenburg and Schrodinger

Mar 8, 1926

You can not measure the position and momentum of particle simultsneously.

Aristotle

Mar 2, 2022

Didn't believe in atomic theory.
Believed in four elements.
Matter made up of pieces of four elements.
Used Obsevation