Alkalis were extracted from ashes, and soaps were prepared by combining these alkalis with fats. Metals were combined to form alloys-for example, copper and tin were mixed together to make bronze-and more elaborate smelting techniques produced iron. Dyes, such as indigo and Tyrian purple, were extracted from plant and animal matter. A variety of drugs such as aloe, myrrh, and opium were isolated from plants. Subsequently, they began to separate and use specific components of matter. Humans began to practice chemistry when they learned to control fire and use it to cook, make pottery, and smelt metals. But as our knowledge increased, humans began to change the composition of the substances as well-clay was converted into pottery, hides were cured to make garments, copper ores were transformed into copper tools and weapons, and grain was made into bread. These endeavors involved changing the shape of a substance without changing the substance itself. Our Stone Age ancestors chipped pieces of flint into useful tools and carved wood into statues and toys. Throughout human history, people have tried to convert matter into more useful forms. Provide examples illustrating macroscopic, microscopic, and symbolic domains. ![]() ![]() Differentiate among hypotheses, theories, and laws.Provide examples of the importance of chemistry in everyday life.Outline the historical development of chemistry.By the end of this section, you will be able to:
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