ATOMIC PROGRESSION

DEMOCRITUS 450BC

• Atomos Theory
• Everything on Earth is
• made up of tiny particles
• called atoms.

ARISTOTLE 450BC

• Earth, Wind, Fire, and
• Water were the four
• basic elements. There
• Was no such thing as
• atoms.

DALTON 1803

• Atoms are like billiard
• balls, one solid particle.

JJ THOMSON 1897

• Atom is big, with stuff in it
• like plum pudding, the
• neutrons and protons are
• plums in the pudding.
• Also did the Cathode ray experiment.

MILLIKAN 1909

• Found the Mass/Charge
• of electrons.
• Also did the Oil Drop
• experiment.

RUTHERFORD 1909

• Discovered that atoms have
• positively charged nuclei.
• Also did the Gold Foil
• experiment

CHADWICK 1932

• Came up with the
• proton, neutron model.
• Atoms are made up of
• a few smaller particles,
• instead of being one particle.