Two cups of the same size are filled to the brim with clear liquids. Cup A holds water. Cup B contains alcohol. Your teacher challenges you to figure out which cup holds water. Because of your great science knowledge, you know that all substances have their own special properties. You and your lab partner add an ice cube to each cup. The ice floats in one liquid. You predict it is water. And the ice sinks in the other liquid. You predict that liquid is alcohol. What type of property of matter did you use to identify the liquids?