Chemistry

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Chemistry

• MAC NOTES Electron Unit
• Electromagnetic radiation differs for wave
  length, wave frequency, and wave energy BUT not
  wave speed (ALL travel at the speed of light).
• As wave length increases, wave frequency and
  wave energy decreases and vice versa.
• Visible (white) light is a part of the
  electromagnetic spectrum and can be remembered as
  ROY G. BIV.
• Electrons absorb and release various types of
  electromagnetic radiation in the form of packets
  of energy called quanta.

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Chemistry

• MAC NOTES Electron Unit
• An absorption spectrum for an element shows a
  colored background with missing bands of visible
  light absorbed by electrons moving from their
  ground state to their excited state.
• An emissions spectrum for an element shows a
  black background with colored bands of visible
  light released (emitted) by electrons moving from
  their excited state to their ground state.
• Electrons can absorb and release energy outside
  visible light, such as Infrared or Ultraviolet.
• The absorption and emission spectra of each
  element is unique, like a finger print.

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Chemistry

• MAC NOTES Electron Unit
• The quantum mechanical model provides a
  four-part address for each electron.
• Quantum number 1 (n) are major energy levels,
  from 1-7.
• Quantum number 2 are sub-energy levels and are
  designated as s, p, d, and f.
• Quantum number 3 are the positions in space
  (orientation) of orbitals.
• Quantum number 4 is the spin (clock-wise or
  counter clock-wise) of each electron in an
  orbital.
• Every electron has a unique 4-part address.

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Chemistry

• MAC NOTES Electron Unit
• The quantum mechanical model is guided by four
  principlesthe Heisenberg uncertainty principle
  the Aufbau principle, the Pauli exclusion
  principle, and Hunds rule.
• Three different notations are used to show the
  arrangement of electrons in the electron cloudan
  electron configuration orbital filling diagram,
  and an electron dot diagram.
• The preceding (smaller) noble gas (column 18
  element) can be used to write an abbreviated
  electron configuration or orbital filling
  diagram.

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