Atomic structure, atomic spectra and electron configurations

• Why are metallic bonds very strong?

  Metallic bonds are very strong due to strong electrostatic forces of attraction between metal cations and delocalised electrons , which take a lot of energy to overcome , leading to high melting points.
• Describe the main features in the appearance of an atomic absorption spectrum?

  An atomic absorption spectrum has black lines on a coloured backround getting closer at a higher frequency
• How does an atomic emission spectrum differ in appearance from an absoprtion spectrum?

  An atomic emission spectrum has coloured lines on a black backround
• Explain, in terms of electronic energy levels, why the atomic absorption spectrum of a particular element is unique?

  1. Energy absorbed causes electrons to move up levels
  2. Energy levels are specific to the element
  3. Energy absorbed relates to frequency
• Explain how the lines in an atomic emission spectrum are formed and why the frequencies of these lines are unique for a given element?

  1. Electrons drop down to lower energy levels
  2. Emitting light
  3. So energy is proportional to frequency / E=hv
  4. Gaps between levels are unique