Electrons in atoms
Download
1 / 14

II. Bohr Model of the Atom - PowerPoint PPT Presentation


  • 114 Views
  • Uploaded on
  • Presentation posted in: General

Electrons in Atoms. II. Bohr Model of the Atom. A. Bohr Model. Niels Henrik David Bohr 1885 - 1962 Born 1885, Copenhagen, Denmark. Father was an eminent physiologist. 1911 - Studied and worked at Cambridge under Sir JJ Thomson

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha

Download Presentation

II. Bohr Model of the Atom

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Electrons in Atoms

II. Bohr Model of the Atom


A. Bohr Model

  • NielsHenrik David Bohr 1885 - 1962

    • Born 1885, Copenhagen, Denmark.

    • Father was an eminent physiologist.

    • 1911 - Studied and worked at Cambridge under Sir JJ Thomson

    • 1912 – worked in Ernest Rutherford’s lab in Manchester, England.

    • 1922 – Nobel Prize in Physics for work on the structure of atoms.


A. Bohr Model

  • e- exist only in orbits with specific amounts of energy called energy levels

  • Therefore…

    • e- can only gain or lose certain amounts of energy

    • only certain photons are produced


B. Line-Emission Spectrum

excited state

ENERGY IN

PHOTON OUT

ground state


Energy of photon depends on the difference in energy levels

Bohr’s calculated energies matched the IR, visible, and UV lines for the H atom

B. Line-Emission Spectrum

6

5

4

3

2

1


B. Line-Emission Spectrum

  • Each element has a unique bright-line emission spectrum.

    • “Atomic Fingerprint”

Helium

  • Bohr’s calculations only worked for hydrogen! 


Electrons in Atoms

III. Quantum Model of the Atom


A. Electrons as Waves

  • Louis de Broglie (1924)

    • Applied wave-particle theory to e-

    • e- exhibit wave properties

QUANTIZED WAVELENGTHS


VISIBLE LIGHT

ELECTRONS

A. Electrons as Waves

EVIDENCE: DIFFRACTION PATTERNS


B. Quantum Mechanics

  • Heisenberg Uncertainty Principle

    • Impossible to know both the velocity and position of an electron at the same time


B. Quantum Mechanics

  • SchrödingerWave Equation (1926)

    • finite # of solutions  quantized energy levels

    • defines probability of finding an e-


Radial Distribution Curve

Orbital

B. Quantum Mechanics

  • Orbital (“electron cloud”)

    • Region in space where there is 90% probability of finding an e-


B. Quantum Mechanics

  • Summary of Quantum Theory

    • Describes mathematically the wavelike properties of e-1 and other small particles.

    • Applies to ALL atoms (unlike the Bohr model)

    • Supports the idea that e-1 exist in regions called orbitals where there is a probability of finding them.

    • Ask me about the 4th bullet point


B. Quantum Mechanics

  • Organization of electrons in atoms

    • Energy levels

    • Sublevels

    • Orbitals


ad
  • Login