In a lab experiment to measure the density of a substance, the two physical properties utilized are mass and volume. This is because density is the measure of mass per unit volume and the SI units are kg/L (or g/mL for more general use). Mass of a substance can readily be found by using a scale or balance (either electronic or balance arm type). The volume can be found a couple of ways. A liquid can be poured into a graduated cylinder and the volume measured. A solid's volume can be measured by dropping it into a graduated cylinder containing a liquid that the solid does not dissolve in and measuring the difference between the two liquid readings. Then divide the mass by the volume to get the density of the substance.