First identified in the 17th century, oxygen is a gaseous, non-metallic element that makes life possible. The chemist and physician John Mayow proved that oxygen was critical to lifeforms, and could be removed by a naked flame and respiration.
A key indication of oxygen’s supreme importance was realized when researchers demonstrated that mice could survive longer in air heated by mercury oxide rather than air heated by using a flame [which consumes oxygen]. They were able to prove that the depletion of “eminently breathable air,” later termed oxygen, directly resulted in the death of a mouse.
Oxygen is also the most plentiful element in the earth’s crust, providing roughly 46% of its mass. Only 21% of the air we breathe is oxygen, nitrogen and other gasses make up the majority.
Like sulfur, selenium, tellurium, and polonium, oxygen is a chalcogen, meaning it’s found in group 16 on the periodic table of elements. It’s believed that chalcogen translates as, “ore maker.”
If you really want details, oxygen’s atomic number is 8, it has an equal number of protons and neutrons, and its atomic weight is 15.999. Oxygen is normally found in an oxidation state of -2, but can also have states of -1, -½, 0, +1, and +2.