In 1772 and 1774 oxygen was discovered by
Scheele and Priestley. Lavoisier was the one that
first described oxygen as the essential for the
combustion of substances. Oxygen means Acid-
producer Oxygen is the must abundant element
on earth. Free oxygen constitutes about 21% by
volume of atmospheric air and 33% by volume of
dissolved air. Combined oxygen make up about
50% by mass of the earth's crust Laboratory
preparation of oxygen. Decomposition of
potassium trioxochlorate (v) 2KClO3(s) = 2KCl(s)
+ 3O2(g) Decomposition of hydrogen peroxide
2H2O2(aq) = 2H2O(l) + O2 Industrial preparation
of oxygen • The liquefaction of air • The fractional... More click here >>>www.rowlandokonko.com/2015/12/oxygen-and-its-properties.html?m=0