Answer: All of these statements are true
Explanation:
Melting point help us to determine if a mixture is pure or has impurities by the virtues of it melting range..
Compound: a thing that is composed of two or more separate elements, basically it is a mixture
Mixture: a substance made by mixing other substances together
so go from there. I don't want to cheat by giving answers, so I hope this is guiding and helpful. please mark brainliest if it is!