Who discovered that water is composed of both hydrogen and oxygen?

Who discovered hydrogen? Henry Cavendish (1731 - 1810) was an English chemist and physicist who spent several years studying the properties of hydrogen and carbon dioxide. In 1776 he discovered that hydrogen was a separate substance. He was the first chemist to produce water from hydrogen and oxygen and to understand that the production of water was essentially related to the loss of the combined weights of the gases.

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The French chemist Antoine Laurent Lavoisier (1743-1794) continued the study of flammable air, repeating Cavendish's experiments, and eventually produced hydrogen and oxygen in the laboratory via the dissolution of metals in acid. He was also able to split water molecules using a heated copper tube. In another experiment he combined hydrogen and oxygen and produced water. These experiments, in 1785, were to prove definitively that H2 and O2 are the basic constituents of water.

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