Bohr's Model

-Bohr (1920's)

•  Rutherford's model was inherently unstable - protons/electrons should attract each other
• Matter emits light when it is heated (blackbody radiation)
• Light travels as photons (particles of light) - waves + particles at the same time
• The energy photons carry depends on their wavelength - shorter the wavelength, the higher the energy

Seperate the white light into colours with a diffraction grating or prism

• Bohr based his model on the energy (light) emitted by difficult atoms
• Each atom has a specific spectra of light
• To explain this emission spectra, Bohr suggested that electrons occupy shells or orbital 

BOHR`S THEORY

• Electrons exist in orbitals
• 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 proton of light

Examples: stars, lightning, aurora (northern lights), fireworks