Evolution of the Atom
By: Kevin Do

Early Greeks
~400 BCE

Aristotle

Thought all matter was made out of 5 elements: Earth, fire, air, water and ether.

Democritus

Thought all matter was created from tiny particles and that the properties of these particles also determined the properties of matter.

1700's

Isaac Newton

Suggested that all atoms either attract or repelled from each other by "forces".

Joseph Priestley

Was the first person to discover that atoms were made of tiny particles

1800's

John Dalton

Discovered that all matter is made up of small particles called "atoms". Also created the Dalton Model

Jöns Jacob Berzelius

First person to measure atomic weights for elements

Michael Faraday

Discovered that the structure of an atom was related to electricity/had an electric component to it

Dmitri Mendeleev

Created the periodic table and arranged it according to atomic weight

George Johnson Stoney

Determined the charge of the atom and created the term "electron"

Eugen Goldstein

Discovered protons

J.J. Thomson

Discovered electrons and created the Plum Pudding Model

Henri Becquerel

Discovered radioactivity

Marie and Pierre Curie

Discovered Polonium, Radium and radioactivity originates
within the atom itself.

1900's

Max Planack

Theorized that matter emits/absorbs
energy in small packets of energy called quantum.

Nagaoka Hantaro

Created the Saturnian model.

Albert Einstien

Confirmed the existence of atoms and molecules using mathematical calculations.

Robert Millikan

Ernest Rutherford

Neils Bohr

Modified the Rutherford Model to create the Bohr Model and discovered that electrons orbit the nucleus of fixed sizes and energies

Louis De Broglie

Introduced the idea that particles have wave like properties

Erwin Schrodinger

Created the Schrödinger wave equation

Paul Dirac

Created a fully relativistic quantum theory.

James Chadwick

Discovered the neutron

Discovered the nucleus of an atom and created the Rutherford Atomic Model

Discovered the fact that all electrons carry the same amount of negative charge