Chemistry AS EL CI 6.1 2.3

HideShow resource information
  • Created by: A.B.
  • Created on: 22-10-13 21:02
View mindmap
  • EL Light and Electrons CI 6.1 2.3
    • Energy Levels
      • An electron in an atom can occupy any one of the fixed energy levels
      • Ground state
        • Closest to nucleus
        • Have lowest energy
      • The difference in energy levels decreases as the electron moves away from the nucleus
    • Absorption spectra
      • Spectrum of visible light with black lines (corresponding to absorptions of energy by electrons)
      • As increasing energy is absorbed (eg moving from 1-6 rather than 1-2) the frequency of light absorbed increases.
      • These spectra are seen from earth when atoms in the chromosphere around stars absorb light.
      • 1. Electrons absorb a 'photon' (package of energy)
        • 2. Excited electrons move up to a higher energy level - they are promoted.
          • What produces lines
          • The electromagnetic radiation absorbed by each of the hydrogen atoms has a definite frequency related to the difference in energy levels.
            •  
              • 3. Electrons drop back to lower energy levels.
                • This is what produces the lines.
                • Since the energy change is different for each transition, the frequency is different and hence so is the colour of the lines.
            • 3. Electrons drop back to lower energy levels.
              • This is what produces the lines.
              • Since the energy change is different for each transition, the frequency is different and hence so is the colour of the lines.
    • Emission Spectra
      • Black background with coloured  lines on it.
        • Correspond to the emissions of energy by electrons
      • An emission spectrum is seen when a chemical burns with a coloured flame.
      • 1. Electrons first absorb a 'photon' (package of energy)
        • 2. Excited electrons move up to a higher energy level - they are promoted.
      • Electron Shells
        • 1st electron shell = max 2 electrons
          • 2nd electron shell = max 8 electrons
            • 3rd electron shell = max 18 electrons
              • 4th electron shell = max 32 electrons
        • An electron will go to its lowest electron shell that is not fully occupied.
        • Learn 4th period as rule is more complex

    Comments

    No comments have yet been made

    Similar Chemistry resources:

    See all Chemistry resources »See all Light and Electrons resources »