Electron Configurations

• Electron Configurations = distributing e- among atomic orbitals
• Ground state configuration = LOWEST energy
• In Hydrogen or 1 e- systems (Bohr) - ALL orbitals in a shell have the SAME energy = n ONLY
• s,p,d,f subshells:

  • SAME energy in a 1 ELECTRON atom = energy based on ELECTRON interactions with the NUCLEUS and OTHER ELECTRONS
• Pauli Exclusion Principle = no more than 2 ELECTRONS per ORBITAL
• Aufbau principle = fill lowest ENERGY orbital first; s<p<d<f
• Hund's Rule

  = FILL up all available ORBITALS first BEFORE pairing electrons

  = Most stable arrangement for e- = degenerate, # of e- are MAXIMIZED
• Core electrons = Noble Gases representing inner electrons
• Valance electrons = outermost electrons with the HIGHEST n
• Same # of valance electrons = same chemical properties
• Paramagnetic = elements with different #s of +1/2 and -1/2 electrons

  • One type of spin over the other
  • attracted to a magnet
• Diamagnetic = species with the same #s of +1/2 and -1/2 electrons

  • NOT attracted to a magnet