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Waveform Audio File Format  |  1995-06-29  |  405.7 KB  |  1 channel  |  22,050 sample rate  |  37 seconds  |  [TEXT/LMAN]
Transcription: An element is a substance that contains only one kind of atom. Atoms cannot be broken down by chemical means, so it is impossible to break up an element into simpler substances by chemical changes. So far, 109 elements have been discovered. 92 occur naturally. The other 17 are artificial elements that can be made only in the laboratory. There are two main kinds of elements, metals and non-metals. Some elements chemically combine with other elements to form substances called compounds.