oxy-, -oxia, -oxic
(Greek: sharp, acute, pointed, keen; sour, acid, acidic, pungent)
Oxygen is necessary for the life processes of nearly all living organisms and for most forms of combustion. It readily forms compounds with nearly all other elements except the inert gases, and it is used in blast furnaces, steel manufacture, chemical synthesis, and in resuscitation, and for many other industrial purposes.
Etymologically, oxygen means "acid-former". It was borrowed from French oxygene, formed in French from Greek oxus, "acid, sharp" plus French -gene, "something that produces". The French word was intended to literally mean "acidifying principle, acid-producer", because oxygen was considered to be the essential element in the formation of acids. It was coined in 1786 by the French chemists Morveau and Lavoisier though the element was earlier isolated by Joseph Priestly in 1774.
Antoine Laurent Lavoisier (1743-1794) named the active portion of the atmosphere oxygen (acid-producer) because it was thought that all acids contained oxygen. In 1789, the French chemist Claude-Louis Berthollet (1748-1822) showed that hydrocyanic acid and hydrosulfuric acid did not contain oxygen. To be sure, they are very weak acids, but it was eventually shown that hydrochloric acid, a strong acid, also did not contain oxygen.
Oxygen is a constituent of animal, vegetable, and mineral substances. It is essential to respiration for most living organisms and is the most important and abundant chemical element in our biosphere. At sea level, it represents 10% to 16% of venous blood and 17% to 21% of arterial blood.
Oxygen is absorbed in a free state by most living organisms. It is produced by green plants from carbon dioxide and water during photosynthesis; carbohydrates such as glucose and starch are also produced by this process. When oxygen is used in cell respiration, the end products are water and carbon dioxide, the latter of which is returned to the atmosphere; as a result, the balance of oxygen and carbon dioxide in the atmosphere is maintained.
When oxygen combines with another substance, the process is called oxidation. When the combination takes place rapidly enough to produce light and heat, the process is called burning or combustion. Oxygen combines readily with other elements to form oxides.
Oxygen from a container is used in cases where there is insufficient oxygen carried by the blood to the tissues (e.g., severe anemia, shock or circulatory collapse, pulmonary edema, and pneumonia) or by mountain climbers, astronauts, or aviators when at heights where the amount of oxygen present in the atmosphere is insufficient to support life.
Frequently oxygen is employed with agents used for the induction of general anesthesia. Following extensive surgery, oxygen is said to reduce reactions to the anesthetic. It is also employed to treat septicemia, gas gangrene, peritonitis, and intestinal obstruction.