Whose work first identified oxygen as an element?

Joseph Priestley, an English scientist, isolated oxygen in 1774 by heating mercuric oxide. Around the same time, Carl Wilhelm Scheele independently obtained the gas in Sweden, though Priestley’s publication came first. Antoine Lavoisier later showed that oxygen was an element and not a compound, and he explained combustion and respiration in modern chemical terms. Because of this, the discovery is often shared across these scientists, with Priestley receiving much of the historical credit. Oxygen became central to modern chemistry.