niel bohr

• what is the name of his model?

  planetary
• what assumptions did Bohr make?

  • electrons travel in a few fixed paths around the nucleus (energy levels)
  • while traveling in their fixed paths the electrons cannot radiate or absorb energy
• what are energy levels?

  regions of space where electrons have fixed energies
• ground state?


  lowest energy state of an electrons
• excited state?


  when an electron gains enough energy for a quantum leap
• what is a quantum leap?

  when an electron 'jumps' from one energy level to another
• the colour of light is determined by its frequency
• frequency?

  number of vibrations per second
• the faster something vibrates the more energy it has
• what is a continuous spectrum?

  emits all wavelengths of light (spectrum of all 7 colours)

  eg: when white light is passed through a prism
• what is a line spectrum?

  the light of 4 colours

  eg: hydrogen gas emits a line spectrum
• difference in energy between one energy level and another is called a?

  quantum of energy
• what does quantized mean?

  ie: we say that the energy of an electron is quantized

  energy can only have certain values
• what is the name given the the number an energy level has?

  principal quantum number (n)
• what is the maximum of electrons that can be in an orbital?

  2n squared
• when an elections jumps back down from an excited state if emits light of the same amount of energy as it lost jumping back down
• Bohr concluded that?

  • The positively charged nucleus is surrounded by negatively charged electrons moving in fixed paths;

  • while travelling in their fixed paths the electrons cannot radiate or absorb energy;

  • the regions of space where electrons have fixed energies are called energy levels;

  • electrons in the Bohr model can never be in between two energy levels;

  • each energy level can accommodate a maximum of 2n2 electrons;

  • electrons located close to the nucleus has less energy and those further away have more energy;

  • to change energy levels an electron must absorb or release energy.
• Balmer Series?

  a series of lines in the electromagnetic spectrum due to electron transitioning from higher energy levels to n=2
• Lyman Series?

  a series of lines in the ultra violet region due to electrons transitioning from higher energy levels to n=1
• atomic emission spectrum of an element is like a fingerprint
• what was wrong with boars model?

  Bohr’s model of the atom could explain the structure of the hydrogen atom however it could

  not provide an acceptable explanation for the spectra of atoms containing more electrons.