Abundance

Name:
Abundance
Detailed information:
The relative amount (% by weight) of a substance in the earth's crust, including the atmosphere and the oceans. (1) The abundance of the elements in the earth's crust is:
Rank	Element	% by wt.
1	Oxygen	49.2
2	Silicon	25.7
3	Aluminum	7.5
4	Iron	4.7
5	Calcium	3.4
6	Sodium	2.6
7	Potassium	2.4
8	Magnesium	1.9
9	Hydrogen	0.9
10	Titanium	0.6
11	Chlorine	0.2
12	Phosphorus	0.1
13	Manganese	0.1
14	Carbon	0.09
15	Sulfur	0.05
16	Barium	0.05
	all others	0.51
(2) The percentages of inorganic compounds in the earth's crust, exclusive of water, are:
(1) SiO2	55	(2) Al2O3	15	(3) CaCO3	8.8
(4) MgO	1.6	(5) Na2O	1.6	(6) K2O	1.9
(3) The most abundant organic materials are cellulose and its derivatives, and proteins.Note: In the universe as a whole, the most abundant element is hydrogen.