Astronomy: General

A Dictionary of Astronomy World Encyclopedia Further reading

elements, abundance of

A Dictionary of Astronomy | 1997 | Copyright

elements, abundance of The relative amount of each element or isotope in a given object such as a planet, star, or galaxy. Cosmic abundance refers to the proportions in the Universe as a whole. The amount of an element may be expressed either as the number of atoms, or by mass. The standard cosmic abundance is based on that of the Solar System, which has been determined from the Sun's spectrum and from analysis of meteoric debris. The cosmic abundance is dominated by hydrogen, with about 25% helium by mass and all remaining elements amounting to less than 2%.

cosmic abundance of the most common elements
Element	Percentage abundance by mass	Percentage abundance by number of atoms
Hydrogen	73.5	92.1
Helium	24.9	7.8
Oxygen	0.73	0.061
Carbon	0.29	0.030
Iron	0.16	0.004
Neon	0.12	0.008
Nitrogen	0.10	0.008
Silicon	0.07	0.003
Magnesium	0.05	0.002
Sulphur	0.04	0.001
Argon	0.02	0.001
Nickel	0.01	0.0002

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

"elements, abundance of." A Dictionary of Astronomy. 1997. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>.

"elements, abundance of." A Dictionary of Astronomy. 1997. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O80-elementsabundanceof.html

"elements, abundance of." A Dictionary of Astronomy. 1997. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-elementsabundanceof.html

Learn more about citation styles

abundance of elements

World Encyclopedia | 2005 | Copyright

abundance of elements Universe: It is estimated that up to 99% of the known universe is made up of hydrogen and helium, with hydrogen in a ratio of 20:1 to helium and some 10,000:1 of other elements. The next, in order, are oxygen, carbon, nitrogen, silicon, magnesium, neon, sulphur and iron.

Earth's crust¹	%	Living things	%	Sea water²	%
¹ Igneous rocks in the lithosphere
² Average ocean concentration
Oxygen	46.6	Oxygen	62.0	Oxygen	85.7
Silicon	27.7	Carbon	20.0	Hydrogen	10.7
Aluminium	8.1	Hydrogen	10.0	Chlorine	1.9
Iron	5.0	Nitrogen	3.0	Sodium	1.1
Calcium	3.6	Calcium	2.5	Magnesium	0.1
Sodium	2.8	Phosphorous	1.14
Potassium	2.6	Chlorine	0.16
Magnesium	2.1	Sulphur	0.14
Titanium	0.44	Potassium	0.11
Hydrogen	0.14

Cite this article
Pick a style below, and copy the text for your bibliography.

MLA
Chicago
APA

"abundance of elements." World Encyclopedia. 2005. Encyclopedia.com. 30 May. 2012 <http://www.encyclopedia.com>.

"abundance of elements." World Encyclopedia. 2005. Encyclopedia.com. (May 30, 2012). http://www.encyclopedia.com/doc/1O142-abundanceofelements.html

"abundance of elements." World Encyclopedia. 2005. Retrieved May 30, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-abundanceofelements.html

Learn more about citation styles

Free newspaper and magazine articles

	Standard abundance distribution of elements in the universe and magic numbers... Magazine article from: American Journal of Applied Sciences; 1/1/2004
	Robbins and Malthus on scarcity, abundance, and sufficiency: the missing... Magazine article from: The American Journal of Economics and Sociology; 10/1/2010
	New atomic data for trans-iron elements and their application to abundance... Magazine article from: Canadian Journal of Physics; 4/3/2012