to know the density of each liquid, you simply have to weigh each bottle and record them separately. Then, as the formula of density says grams per volume, first convert the volume f the containers to milliliters(ml) then you divide each mass recorded by the volume of each bottle respectively and the one who will have a density of 1.0g/ml will be water and no one else.... Hope it helped someone
Most likely an altimeter,
microscopes can be too heavy to carry outside,
x-ray diffraction is used to determine the molecular structure of a crystal so that is not likely to be helpful,
but an altimeter determines the altitude of an object on a fixed level, so that can be useful during a field investigation
hydrometers-measure gravity of liquids, probably not useful for a field investigation
