The density of a metal refers to how much a certain amount of it weights. The density is a physical property of the metal that remains constant no matter how much or how little the metal you have. You can calculate the density by measuring the volume and mass of the metal in question. Common density units include pounds per cubic inch and ounces per cubic inch.
Determine the mass of the metal by using a scale. Take the measurement in pounds. If the scale shows a result in ounces, divide the result by 16 to convert from ounces to pounds.
Determine the volume of the metal either through measuring the dimensions or measuring the displacement. If the object is a regular shape, such as a cube, you can measure the dimensions and use the volume formula for that shape, such as cubing the side length of a cube. For more volume formulas, see resources.
If the metal is awkwardly shaped, you can calculate the volume using the displacement method. Fill a beaker half-way and record the volume of water. Insert the metal into the water and record the new volume of water. Subtract the initial volume of water from the final volume to determine the volume of the metal.
Divide the mass by the volume to calculate the density of the metal. For example, if the mass was 7.952 pounds and the volume was 28 cubic inches, the density would be 0.284 pounds per cubic inch.
You can compare the calculated density of the metal to a density table (see resources) to predict what type of metal you have. For example, 0.284 pounds per cubic inch is the density of iron.