If I remember correctly- the more air present in the material the more damping of the sound waves occurs, giving it a higher transmission lossSo for example plasterboard (gypsum) would give better insulation than a sheet of glass, of course you wouldn't use either of these on your floors, but you get the ideaI guess pile carpets would do a better job when compared to wooden floors.
I guess you mean how many moles of the reactant aluminumRemember the concept that 1 mole of the element would weigh the same as the atomic mass in gramsFor that we just divide the mass of aluminum by its molar mass to find number of molesOther info is useless molar mass of aluminum is 27 so .61/27 about .02252 moles of Al atoms.
