Matter & Energy

Matter is composed of atoms or groups of atoms called molecules. The arrangement of particles in a material depends on the physical state of the substance. In a solid, particles form a compact structure that resists flow. Particles in a liquid have more energy than those in a solid. They can flow past one another, but they remain close. Particles in a gas have the most energy. They move rapidly and are separated from one another by relatively large distances.

Physical Properties of Liquids

F. Miscibility

Miscibility is a measure of how easily different liquids will dissolve when mixed together. Miscibility depends on the polarity of a liquid’s molecules. For example, water will mix with alcohol because they are both polar liquids, so their molecules attract one another. But water will not mix well with oil, which is a nonpolar liquid. Oil floats on top of water because the polar water molecules are much more strongly attracted to each other than to the oil molecules. The rule for determining miscibility is that “like dissolves like.” Polar liquids are miscible with other polar liquids, while nonpolar liquids are miscible with other nonpolar liquids.