Thomsons Discovery of Electrons

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Thomsons Discovery of Electrons

• 1897, JJ Thomson discovered that there were
  things inside the atom.
• Used a cathode-ray tube to discover electrons.
• Proposed a new model of the atom The
  plum-pudding model.

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The Modern Atomic Theory

• The Modern Atomic Theory there are regions
  inside the atom where electrons are likely to be
  found.
• These regions are called electron clouds.

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How Small Is an Atom?

• Three One-Hundred-Millionths of a Centimeter!
  Scientists know that aluminum is made of
  average-sized atoms. An aluminum atom has a
  diameter of about 0.00000003 cm.

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