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.


Celluloid, originally the trade name and now the common name of a synthetic plastic made by mixing pyroxylin, or cellulose nitrate, with pigments and fillers in a solution of camphor in alcohol. When heated, the substance is pliable or plastic and can be molded into a variety of shapes. Upon drying and cooling, the material becomes hard. In the United States celluloid was invented by John Hyatt, who was trying to win a $10,000 award for finding a substitute for ivory in making billiard balls. Hyatt failed to win the prize, but he received a patent for his discovery in 1870. The patent was disputed by the British inventor of Xylonite, a similar product.

Celluloid is transparent and colorless and in paste form can be colored or rolled or molded into specific shapes. Some of its advantages are that it is inexpensive and durable, takes a high polish, does not warp or discolor, and is not affected by moisture. It is, however, highly flammable, and although modifications in manufacture have reduced the dangers of fire, it has been largely superseded by other materials. Celluloid is used in making combs, brushes, and buttons.