Development of the Atomic Theory

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Development of the Atomic Theory Part 1
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Remember earlier this year we talked about the
chemists
Aristotle VS Democritus
The world is made up of empty space tiny
particle. These particles are ATOMOS - means
indivisible. The atom is the simplest unit of
matter.
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Antoine Lavoisier
1782 He made measurement of chemical change in a
sealed container. - Concluded that when a
chemical reaction occurs, matter is neither
created or destoryed, but only changed.
Law of Conservation of Matter
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1799 John Proust - observed that the composition
of water is always 11 hydrogen 89 oxygen
Law of Definite Proportion
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1803 John Dalton - proposed the 1st Atomic Theory

• Main Points
• All matter is composed of atoms (indivisible
  parts)
• Atoms are indestructible can not be divided
  into smaller parts Relates to Law of conservation
  of matter
• All atoms of one element are exactly alike,
  because they have the same mass.
• Atoms of one element are different from atoms of
  other elements. Relates to Law of definite
  Proportion

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John Daltons Atom
Solid ball Model
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Atomic Theory is the idea that matter is made up
of fundamental particles called atoms.
Experiments in the 19th began to suggest that
atoms were NOT fundamental, but made up of
smaller particle.