What the ultimate Natural Units of material are?
What is a chemical element?
The first identified chemical element is oxygen.
J. Becher (1635-1682) studied fire, and considered burning released
Metal ® Calx + phlogiston
Priestley learned that part of air supported combustion.
He found nitrous air (actually NO) combined with 1/5th
of good air to produce water-soluble air.
C.W. Scheele probably discovered oxygen in 1773.
Aug.1, 1774, Joseph Priestly obtained a colorless gas by heating mercury
oxide (mercurius calcinatus per se). Candles burn brightly in his
Priestley came by Paris and told Lavoisier of his experiment.
Lavoisier repeated the experiment, and considered oxygen a chemicl element,
after much work.
Priestley accepted Lavoisier's conclusion only at old age.
Oxygen, the most abundant element of Earth crust (mostly SiO2,
and Al2O3) exists as O2 and O3
(ozone) in the atmosphere.