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.


Acetone, a colorless, flammable liquid, the simplest of the organic chemicals called ketones. Completely soluble in water and organic solvents, acetone is itself an important solvent and is used both in the laboratory and in industry. Also called dimethyl ketone and 2-propanone, it has a mild, pleasant odor, boils at 56° C (133° F), and melts at -95° C (-139° F). Enormous quantities are used as solvents for cellulose acetate in the production of rayon and as a gelatinizing agent for explosives. Acetone is also used as an ingredient in lacquer solvent and to dissolve gums and resins. It is the solvent in rubber cement and in some cleaning fluids. Acetone can be prepared in the laboratory by oxidation of isopropyl alcohol, by heating calcium acetate, or by fermenting sugar with certain bacteria. Currently, most acetone is produced by the Hock process, which uses as raw materials benzene and propene to produce acetone and phenol.