Using a two-pan balance (and a digital scale to see how accurate they were!), fifth graders designed an experiment to see if the mass of one of the chemicals (i.e. salt) added to the mass of another chemical (i.e. water) would equal the mass of both together. If the mass of the two combined equaled the mass of each of the two seperately, this would give more evidence that even if we physically couldn't see them, that they must be there. Great work fifth graders!