Joseph Priestley was an English chemist, natural philosopher, separatist theologian, grammarian, multi-subject educator, and liberal political theorist. He published over 150 works, and conducted experiments in several areas of science.
Portrait of Priestley, 1801
Priestley's birthplace (since demolished) in Fieldhead, Birstall, West Yorkshire – about six miles (10 km) southwest of Leeds
Mary Priestley, by Carl F. von Breda (1793); daughter of ironmaster Isaac Wilkinson, sister of industrialist John Wilkinson
A redacted version of A New Chart of History (1765); Priestley believed this chart would "impress" upon students "a just image of the rise, progress, extent, duration, and contemporary state of all the considerable empires that have ever existed in the world"
Oxygen is a chemical element; it has symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is the most abundant element in Earth's crust, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula O2. Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.
Oxygen-filled discharge tube glowing purple.
Joseph Priestley is usually given priority in the discovery.
Antoine Lavoisier discredited the phlogiston theory.
Robert H. Goddard and a liquid oxygen-gasoline rocket
