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The History of an Atom Bohrs Contribution

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The History of an Atom Bohrs Contribution Powered By Docstoc
					     The History of an Atom:
        Bohr’s Contribution


Researched by Conor MacGregor
              &
         Sohaib Qadri
                             Previous Work
• John Dalton proposed a model of the atom
• J.J. Thomson discovered the electron
• Ernest Rutherford had recently suggested the atom
  had a miniature, dense nucleus surrounded by a
  cloud of electrons.
• Max Planck established quantum theory
  (wavelength and frequency of any wave were
  related, and that the frequency was proportional to
  the energy of the wave)
                             About Bohr

•   Born and lived in Copenhagen, Denmark
•   Full name; Niels Henrik David Bohr
•   Won Nobel Prize for Physics in 1922
•   Renown Physicist in his age
•   Studied under Ernest Rutherford and
    worked with J.J. Thomson
                                                 Bohr’s Theory
•   Bohr proposed that when an electric current is passed through a pure elemental
    gas, the gas gives off a certain type of unique color barcode that is called a line
    spectra.
•   Bohr believed that the atom could only give off certain amounts of energy and
    suggested that electrons occupy specific energy levels in the atom.
•   In Bohr’s thinking, the energy levels can be considered concentric circles
    around the nucleus and when an electron is stimulated it will jump to higher
    energy levels, but it will eventually drop back down to the lowest energy level.
    When an electron jumps it releases light and color which is what Bohr thought
    created the line spectra
•   Bohr also said that each level could only hold a certain number of electrons.
• Depiction of Bohr's Theory on the Atom
                             After Bohr

• Erwin Schrödinger forms new, more
  accurate depiction of the atom
  (Schrodinger’s Atom vs. Bohr’s Atom)
• James Chadwick discovers neutron
                               Questions
• 1. What did Bohr’s theory state about how
  much energy an atom could give off?
• 2. What did Bohr’s theory state about the
  movement of atoms?
• 3. How does Bohr’s theory support
  Rutherford’s experiment?
• 4. How has quantum physics reshaped
  atomic theories?

				
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