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.

Dyeing

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Dyeing, process of coloring materials, such as textile fibers, so that the coloring matter becomes an integral part of the fiber. Dyes, or dyestuffs, are soluble compounds that can be either absorbed and retained by the fiber or chemically combined with it. Dyes are generally fast—that is, they retain their color in the fiber throughout the textile-making process and under exposure to normal wear, including sunlight, water, and detergent washing. Pigments are insoluble coloring compounds. See Textiles; Color.