What is covalent character, how does it arise. List a compound it does affect and explain the resulting properties covalent character affects.

Covalent character occurs in ionic bonds when the postive (usually metal) ion is highly charge dense and can polarise the counter ion causing electrons to be shared between the two ions rather than electrons being completely localised on the anion.
Example includes any sensible Lithium/magnesium/aluminium compound (or many others)
Covalent bonds are known to be stronger than ionic bonds so results in higher atomisation energies whilst also reducing melting point due to weaker inter-molecular forces experienced by covalent compounds.