electron configuration

• Subshells within an orbital have different energies due to their distance from the nucleus.
• Electron configurations are written with subshells listed from highest to lowest energy, starting with s, then p, d, f.
• Electrons fill up orbitals starting with s, then p, then d, etc., until all electrons are placed.
• Auf bau electron configuration rule: electrons fill lower-energy atomic orbitals before filling higher-energy ones
• Hunds rule:they must first occupy the empty orbitals before double occupying them.
• When first occupying a sublevel spin on electrons can be random
• Opposite spin: offsets the repulsion (- and a +)
• The maximum number of electrons in any orbital is 2 (spin up or down).
• Electrons


  Arranged in energy levels or shells around the nucleus of an atom
• The shell nearest the nucleus is going to represent the lowest energy level or shell
• Electron configuration


  the arrangement of electrons in orbitals around an atomic nucleus .Filling up each shell in turn starting with the lowest
• Maximum number of electrons per shell


  • First shell: 2
  • Second shell: 8
  • Third shell: 8
  • Fourth shell: 2
• s sublevel


  • Spherical shape
• p sublevel


  • Dumbbell shape
• The number of energy levels is equal to the number of sublevels
• s sublevel


  Can hold up to 2 electrons
• s block


  First two columns of the periodic table (group 1 and group 2)
• p sublevel


  Can hold up to 6 electrons
• p block


  Group 13 to group 18 in the periodic table