Development of the Atomic Model

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Development of the Atomic Model
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400 B.C. Democritus

• He thought atoms were un-cuttable
• Also atoms are hard small particles

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1808-Dalton

• He believed that all substances are made of
  atoms.
• Atoms of the same element are exactly alike, and
  with different elements are different.
• He made experiments in combining elements.

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1897-Thomson

• The atomic structure was led to the plum-pudding
  model.
• Discovered the electron
• He made a cathode-ray tube experiment

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1911-Rutherford

• The electrons move in empty space in the atom
• Discovered the nucleus
• Performed the gold foil experiment
• Inside are small negatively changed particles in
  a atom

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1913-Bohr

• Electrons travel in definite paths orbit the
  nucleus
• The electrons jump from path to path.

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1926-Schrodinger

• The electrons path cannot be predicted
• The electrons are found in the electron cloud not
  paths

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Word reminder

• Democritus- snowflake or popcorn .
• Dalton-ball
• Thomson-chocolate chip cookie
• Rutherford- sprinkle doughnut
• Bohr- plants
• Schrodinger-electron cloud

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1)Who believed that the electrons were found in
electron cloud ? 2) Who thought that jump
from path to path?

• A) Bohr
• B) Schrodinger
• C) Rutherford
• D) Thomson

• 2) A) Bohr
• B) Dalton
• C) Democritus
• D) Rutherford

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Who believed that atoms are uncuttable?2)Who
believed that atoms of the same element are
exactly alike?

• 1) a) Dalton
• b) Democritus
• c) Thomson
• d) Bohr

• 2) a ) Dalton b ) Bohr
• c ) Rutherford
• d ) no clue.

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Thomson conducted what experiment?

• A) Experiment in combining elements.
• B) Gold foil experiment
• C) Cathode-ray tube
• D) Electron clouds

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THE END (