In this chapter, you should be able to:

• describe the number and relative energies of the s, p, and d orbitals for the principal quantum number 1, 2 and 3 and also the 4s and 4p orbitals
• describe the shape of s and p orbitals
• state the electronic configuration of atoms and ions given the proton number and charge, using the convention 1s2 2s2 2p6, etc
• explain and use the term ionization energy, and the factors influencing the ionization energies of elements
• use ionization energy data to:
  • explain the trends across period and down a group of the Periodic Table
• deduce the electronic configurations of elements
• interpret successive ionization energy data of an element within the Periodic Table.