Outline of Chemistry - Atomic Theory

Atomic Theory

The Atomic Model Timeline

• The idea of what an atom is has changed over time.
• Different scientists and their discoveries have led to the development of the current model of an atom.
• Other examples include:
  • The solar system (BIG made SMALL)
  • The biological cell (SMALL made BIG)

The Democritus Model

• A Greek philosopher
• He conceived the idea of the atom to describe matter.
• Atom comes from the word atomos which means "indivisible".
• He believed that matter was finite (had a limit)
• He believed the smallest piece of matter was an indestructible and indivisible particle which he called the "atom".

The John Dalton Model

J.J. Thompson: The Plum Pudding Model