When 25 g of diethyl ether (C4H10O) is converted to vapor at its boiling point, about how much heat is absorbed? (heat of vaporization, ΔHvap = 15.7 kJ/mol)

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.

May someone me with these science questions