(DA) Oct. 15, 2010: Neils Bohr

Bohr (1920s) 

• Rutherford's model was inherently unstable
  - Protons and electrons should attract eachother
• Matter emits light when it is heated (black body radiation)
• Light travels as photons
  
  
  PHOTONS
• The energy photons carry depends on their wavelengths

Bohr based his model on the energy (light emitted by different atoms. Each atom has a spectra of light. To explain this emission spectra, Bohr suggested that electrons occupy shells or orbitals

 

If given enough energy, an atom can move down or up levels of the orbitals.

BOHRS THEORY:

• Electrons exist in ortibals
• When they absorb energy they move to a higher orbital
• As they fall from a higher orbital to a lower one they release energy as a photon of light.