9781422279519

Understanding the Periodic Table

discovered and whose prop- erties had been explored. One of the first attempts to arrange the known elements into some sort of pattern was in 1789, when Antoine Lavoisier, a French chemist, classified the known elements as gases, metals, nonmetals, or earths. Others continued the attempt to organize. For example, in 1829, Johann Döbereiner found groups of three elements with sim-

Lavoisier is sometimes called the father of modern chemistry.

ilar properties. He pointed to the fact that lithium, sodium, and potassium shared chemical properties. These three elements are all metals, they have similar melting and boiling points, and are nearly the same density .

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