Density: Layers of Liquids

Kit No. 114

SCIENTIFIC CONCEPTS AND PROCESSES

• A substance has characteristic properties, such as density, which are independent of the amount of sample
• A mixture of substances often can be separated into the original substances using one or more of the characteristic properties

This activity provides students with experiences that allow them to develop an operational definition of density. Students are provided with liquids of different viscosity and density and asked to observe and predict, based on their observations, the relative density of each. They then test their predictions and develop an understanding of density by preparing sequences of liquid layers. They are given values for the density of each liquid and asked to use this information to estimate the density of an unknown solid. Finally, there is an optional challenge to design and carry out an experiment to determine the density of a fourth liquid.