THE PROPERTIES OF MATTER

History tells us that Archimedes (287 - 212 B.C.), a Greek mathematician and inventor, was given the task by King Hieron of determining whether the King's newest crown was made of pure gold. The King suspected it was not, but he could not allow Archimedes to scratch or damage the crown in any way. It was a complex task for Archimedes until he realized that when the crown was immersed in water, the volume of water that overflowed would be equal to the volume of the crown. This information, together with the weight of the crown, enabled him to determine the density of pure gold and compare it with the density of the metal in the crown. Not all went well for the crown maker, since it turned out that the crown was made from a metal less dense than pure gold. In this way one of the first practical applications of density was born.
Every substance has it own unique value for density. Density measures the amount of mass in a single unit of volume. A lead block has more mass than the same volume of aluminum. We thus say that the density of lead is greater than aluminum. Density also applies to liquids. If we wanted the same mass of water and rubbing alcohol, we would need a greater volume of alcohol because it is less dense than water.
The density of any material can be determined by dividing the mass by the volume. We can write this as a formula:
Density = Mass / Volume

Mass and Volume Labs

Calculating Densities (1)

		This lab shows a method for determining mass and volume of an object based on displacement of water by the object.

Calculating Densities (2)

		This lab demonstrates a method of discerning metals on the basis of density, by calculating the mass and volume of two metal cubes.

Calculating Densities of Solids

		This lab illustrates a method of determining the density of an unknown metal by calculating mass and volume.

Comparing Densities of Liquids

		This lab provides a method for comparing the mass of two liquids to determine which is greater.

Comparing Densities of Solids

		This lab provides a method for comparing the mass of lead and gold, and determining whether a substance is one or the other.

Finding the Mass of an Object

		This lab shows a method for determining the mass of an object suspended in a liquid.

Identification by Density

		This lab demonstrates a method for determining a substance based on comparisons of mass and volume.

Weight and Density

		This lab explains a method of determining a substance based on density.