Oxygen is the 3rd most abundant element in the known universe. Only
hydrogen and helium, in that order, are more abundant. The big bang theory of creation
asserts that all the elemental oxygen on earth was created late in the life of a dying star.
On earth, oxygen is the most abundant element in the lithosphere (land), hydrosphere
(water), and atmosphere (air). More precisely, the lithosphere is all the crust or solid,
upper portions of the Earth; the hydrosphere includes all the rivers, lakes, seas, and
oceans; and the atmosphere is the gas-filled space above and near the earth. Atomic
oxygen is chemically and biologically reactive and primarily exists as molecular
oxygen (O2, two like atoms combined), or in combination with certain elements
(primarily metals). Oxygen forms reactive intermediates and free radicals including
peroxide, superoxide and hydroxyl radical. The latter is said to be the most reactive
species known in chemistry. Oxygen has a unique arrangement of electrons that is
conducive to one-electron transfer reactions that can produce oxygen free radicals and
cause biological oxidant stress. However, oxygen is especially suited to serve as the
terminal acceptor of electrons in the biological process of electron transfer that is
linked via coupled reactions to oxidative phosphorylation that creates adenosine
triphosphate (ATP), the universal storage and transfer form of energy for all aerobic
life on earth.
Keywords: Atmosphere, Aufbau order, Big bang, Burning, Christ’s last breath,
Combustion, Dmitri Mendeleev, Double bond, Elemental oxygen, Final electronacceptor,
Free radicals, Hydrogen peroxide, Hydrosphere, Hydroxyl radical,
Inflation, Lithosphere, Nucleosynthesis, Ozone, Periodic table, Photosynthesis,
Sir Fred Hoyle, Superoxide dismutase, William A. Fowler.
