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Inevitably, the harmful effects of some substances will outweigh their benefits, and their use will have to be limited.
Yet, the positive impact of chemistry on society as a whole seems beyond doubt.
For Aristotle, these “elements” were not building blocks of matter as they are thought of now; rather, they resulted from the qualities imposed on otherwise featureless prime matter.
Consequently, there were many different kinds of earth, for instance, and nothing precluded one element from being transformed into another by appropriate adjustment of its qualities.
Rather than starting with such modern concepts, though, a fuller appreciation of the subject requires an examination of the historical processes that led to these concepts.The world’s reserves of fossil fuels ( oil, natural gas, and coal) will eventually be exhausted, some as soon as the 21st century, and new chemical processes and materials will provide a crucial alternative energy source.The conversion of solar energy to more concentrated, useful forms, for example, will rely heavily on discoveries in chemistry.The chlorofluorocarbon problem illustrates how difficult it is to anticipate the overall impact that new materials can have on the environment.Chemists are working to develop methods of assessment, and prevailing chemical theory provides the working tools.