Everyone is familiar with liquid water, ice and water vapour, but what are the differences between these three states of matter? Solids, liquids and vapours of the same substance differ in the motion of the molecules and the distance between them. Duration 04:53
A mixture of oil and water usually separates quickly, but a range of substances act as emulsifiers. In this activity, students test a range of things commonly found in the kitchen to see which stabilises an oil and water emulsion. Colloids such as these are often found in foods.
Separating Sand and Salt
In this experiment students separate a mixture of sand and salt, illustrating the fundamental means of separating a mixture of an insoluble material from one which is soluble.