Oxygen is a chemical element with symbol O and atomic number 8. A member of the chalcogen group on the periodic table, it is a highly reactive nonmetal and oxidizing agent that forms oxides with most elements as well as other compounds. By mass, oxygen is the most abundant element in the Earth's crust and the third-most abundant in the universe, after hydrogen and helium. Two atoms of the element can bind to form dioxygen, a colorless and odorless gas that constitutes 20.8% of the Earth's atmosphere, produced by photosynthesis from water and carbon dioxide. Oxygen is present in water, proteins, nucleic acids, carbohydrates, and fats. Its name was coined in 1777 by Antoine Lavoisier, whose experiments helped to discredit the then-popular phlogiston theory of combustion and corrosion. Common uses of oxygen include residential heating, internal combustion engines, production of steel, plastics and textiles, brazing, welding and cutting of steels and other metals, rocket propellant, oxygen therapy, and life support systems in aircraft, submarines, spaceflight and diving.

Read more: https://en.wikipedia.org/wiki/Oxygen

_______________________________ Today's selected anniversaries:

917:

Liu Yan declared himself emperor, establishing the Southern Han state in southern China, at his capital of Panyu (present-day Guangzhou). https://en.wikipedia.org/wiki/Liu_Yan_(emperor)

1781:

American Revolutionary War: French naval forces handed Britain a major strategic defeat in the Battle of the Chesapeake. https://en.wikipedia.org/wiki/Battle_of_the_Chesapeake

1882:

A group of London school boys led by Bobby Buckle founded Tottenham Hotspur F.C. so they could continue to play sports during the winter months. https://en.wikipedia.org/wiki/Tottenham_Hotspur_F.C.

1921:

Popular American comedian Roscoe "Fatty" Arbuckle attended a party during which a woman was fatally injured; although he was eventually acquitted of manslaughter, the trial's scandal derailed his career. https://en.wikipedia.org/wiki/Roscoe_Arbuckle

1977:

NASA launched the robotic space probe Voyager 1, currently the farthest spacecraft from Earth. https://en.wikipedia.org/wiki/Voyager_1

_____________________________ Wiktionary's word of the day:

skitter: 1. (intransitive) To move hurriedly or as by bouncing or twitching; to scamper, to scurry. 2. (intransitive) To make a scratching or scuttling noise while, or as if, skittering. 3. (transitive) To move or pass (something) over a surface quickly so that it touches only at intervals; to skip, to skite. https://en.wiktionary.org/wiki/skitter

___________________________ Wikiquote quote of the day:

The artist should not only paint what he sees before him, but also what he sees in himself. If, however, he sees nothing within him, then he should also refrain from painting what he sees before him. Otherwise his pictures will be like those folding screens behind which one expects to find only the sick or the dead.   --Caspar David Friedrich https://en.wikiquote.org/wiki/Caspar_David_Friedrich