Atomic Structure

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Atomic Structure
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Aristotle

• Greek Philosopher
• Born into aristocracy
• Student of Plato
• Studied made contributions to all subjects
• No particle nature to matter called it hyle
• Accepted until 17th century

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Aristotle Model

• Four Basic Qualities of Matter
• Earth
• Air
• Fire
• Water

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Democritus

• 460 370 BC
• Greek Philosopher
• Matter was made of small pieces that were
  indivisible
• Atomos
• Hard particles made of the same substance
• Particles could move join together

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Dalton

• 1766 1844
• English teacher scientist
• Studied gases (weather)
• Atomic Theory of 1803
• Matter composed of particles called atoms
• Atoms were indivisible, indestructible, atoms of
  the same elements were alike

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Dalton Atomic Model
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Rutherford

• 1871 1937
• New Zealander
• Discovered that the atom is mostly empty space
• Mass of atom is in the nucleus (10,000X less)
  has a positive charge
• Electrons scattered around outside edge

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Rutherford Atomic Model
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Bohr

• 1885 1962
• Danish Physicist
• Nobel Prize in quantum mechanics in 1922
• Electrons in set orbits around the nucleus (like
  planets around Sun)
• Chemical properties are determined by the number
  of outermost electrons

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Bohr Atomic Model
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De Broglie

• 1892 1987
• Electrons do not have a fixed position
• Electrons occupy an area called the electron cloud