Get Your Science On: Separation of Mixtures Part 2

Last time we saw that we can separate mixtures by using size and magnetism. This time we use density to separate a mixture. This process is used to separate different types of plastics so that they can be recycled.

Density of a material is its mass divided by its volume. A certain material will have a constant density, no matter how much of it you have. Materials will float in a liquid if they are less dense than the liquid and they will sink if they are more dense than the liquid. The density of water can be increased by adding sugar or salt and decreased by adding isopropyl alcohol.

This video features Erika Maass, an instructor at the University of Namibia. This partnership has been made possible by the generous support of B2Gold Namibia. More details about the Little Shop of Physics B2Gold Partnership can be found here.