Obtain some red or blue liquid food coloring from your kitchen or local grocery. Prepare two glasses or transparent plastic cups containing equal amounts of water, one drawn from the cold tap and the other drawn from the hot tap. Drop one drop of food coloring into each cup and observe what happens. (Do not stir once the food coloring has been added.)
a. Describe the changes that take place over several minutes in time until the food coloring is well dispersed in both cups. What differences do you note between the cups with the cold and hot water?
b. Develop an explanation for your observations. Do they suggest the presence of tiny particles such as molecules or atoms?