spectra

• Bohr model

  • small positively charged central nucleus
  • lowest energy level - ground state
  • electrons gain energy and move to a higher energy level in an excited state
  • if an electrons is removed it is in an ionisation state
  • electrons cannot orbit the space between energy levels
  • energy of a photon is dictated by the difference in energy levels
  • when an electron is not attached to an atom it is at an energy level of zero
• absorption spectum is a continuous spectrum with black lines which show which elements are present, the black lines are where electrons have jumped to a higher energy level absorbing a photon of light
• emission spectrum is black with coloured lines when an electron moved down in energy level it releases a photon of light, each electron releases a differet frewuency of light producing the colour
• continuous spectrum is a full spectrum of light
• absorption lines in the spectrum of sunlight provide evidence for the composition of the suns outer atmosphere