electronic configuration

• what is the sub shell order

  1s2 2s2 2p6 3s2 3p6 4s2 3d10 ...
• how to you write an electron configuration short

  put square brackets around the noble gas closest to the atom then continue from where the noble gas end

  eg: Mg-1s2 2s2 2p6 3s2

  short: Mg-[Ne}3s2
• what are the two anomalies

  -copper

  -chromium
• electron configuration of copper

  1s2 2s2 2p6 3s2 3p6 4s1 3d10
• electron configuration of chromium

  1s2 2s2 2p6 3s2 3p6 4s1 3d5
• define first ionisation energy

  the energy needed to to remove 1 mol of electrons from 1 mole of gaseous atoms to produce 1 mol of gaseous ions