ATOM HISTORY

DEMOCRITIES

ATMOS THEORY

• Matter was made up of miniscuall particles called atoms
• The atom is invisible
• Mattter can not be devided infinitly

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WATER,EARTH,FIRE,AIR

• 4 elements =basic building blocks of matter
• Matter is actually infinitely divisible
• Completely disagrees with Democrituees theory
• ( Democritueess ends up being more right )

DALTON

BILLIARD BALL

• All matter consists of tiny particles
• Atoms are indestructible and unchangeable
• Elements are characterized by the mass of there atoms
• When Elements react, their atoms combine in simple, whole-number ratios

THOMSON

PLUM POUNDING

• Preformed the cathode ray experiment
• identified that electrons inside an atom could show
• model of an atom as a sphere of positively charged matter with negatively charged electrons surrounding them
• stated that electrons were positioned by electrostatic forces

RUTHERFORD

POSITIVELY CHARGED NUCLES

• Preformed the gold foil experiment
• positively charged central core to the atom
• Decided to call it the nucleus
• the atom was mostly empty space.

MILLIKAN

MASS/CHARGE OF ELECTRON

• Preformed the oil drop experiment
• Electrons charge independently
• Also Millikan's contribution to this hypothesis was to specify the size of the electron's charge.
• Also Millikan's contribution to this hypothesis was to specify the size of the electron's charge.

CHADWICK

PROTONS AND NEUTRONS

• Discovered neutrons
• Neutrons help stabilize protons
• Neutrons always located in the nucleus