I've been completing a past paper; although I'm really stuck on how to answer this, and what the mark scheme means.
Calcium Chloride can be prepared by the reaction of calcium with chlorine gas.
Calcium has a high relative melting point, good conductivity when solid, as well as when molten.
Chlorine has a low relative melting point, poor conductivity when solid, as well as when molten.
Calcium chloride has a high relative melting point, poor conductivity when solid, however good conductivity when molten.
Explain, in terms of bonding and structure, why the properties of the product, calcium chloride, are different from the properties of the reactants, calcium and chloride.
EDIT - 6 mark question