How does a compound's properties compare to those of its component elements? Provide an example.
I don't get this q.
They don't and that's the point of the question.
Two elements combine (with their individual properties). The compound formed usually has completely different properties. For example
Na metal (a soft metal, reacts violently with water, etc) reacts with Cl2 gas (a poisonous gas) to form NaCl (table salt--no reaction with water, hard and not soft, and not toxic).