Physics homework

Full work and explanations, in complete sentences, required for all items. 1) Explain why we cannot be sure that for a sample of an element that has the same number of atoms as a sample of a compound has molecules the element sample has a smaller mass than the compound sample. We cannot be sure because 2) Explain why we cannot be sure that for a sample of an element that has the same number of atoms as a sample of a compound has molecules the element sample has a smaller density than the compound sample. We cannot be sure because 3) If an atom of Na is in the molecules of a compound with an atom of another element, can we say anything about how the mass of the molecule compares to that of the Na atom? 4) For the compound in the previous question, why can't we say that the density of the compound is greater than the density of Na