| Share
 

oxygen

Natural Occurrence and Preparation

Oxygen is the most abundant element on earth, constituting about half of the total material of its surface. Most of this oxygen is combined in the form of silicates, oxides and water. It makes up about 90% of water, two thirds of the human body and one fifth by volume of air. It is found in the sun, and has a role in the stellar carbon cycle (see nucleosynthesis). Oxygen is prepared for commercial use by the liquefaction and fractional distillation of air and more expensively by the electrolysis of water; it is stored and transported under high pressure in steel cylinders. It can also be obtained by heating certain of its compounds, such as barium peroxide, potassium chlorate, and the red oxide of mercury.

Sections in this article:

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on oxygen Natural Occurrence and Preparation from Infoplease:

See more Encyclopedia articles on: Compounds and Elements


Premium Partner Content
HighBeam Research
Documents Images and Maps Reference
(from Newspapers, Magazines, Journals, Newswires, Transcripts and Books)

Research our extensive archive of more than 80 million articles from 6,500 publications.

Additional search results provided by HighBeam Research, LLC. © Copyright 2005. All rights reserved.

24 X 7

Private Tutor

Click Here for Details
24 x 7 Tutor Availability
Unlimited Online Tutoring
1-on-1 Tutoring