Abundances of the Elements in the Earth's Crust

ElementApproximate
% by weight
Oxygen
46.6
Silicon
27.7
Aluminum
8.1
Iron
5.0
Calcium
3.6
Sodium
2.8
Potassium
2.6
Magnesium
2.1
All others
1.5

Given the abundance of oxygen and silicon in the crust, it should not be surprising that the most abundant minerals in the earth's crust are the silicates. Although the Earth's material must have had the same composition as the Sun originally, the present composition of the Sun is quite different. The elemental composition of the human body and life in general is quite different.

These general element abundances are reflected in the composition of igneous rocks.

 Index

Tables

Data Reference
Lutgens & Tarbuck
Ch 2
 
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Common Elements Important in Living Organisms

Element
Symbol
Atomic Number
Percent in Universe
Percent in Earth
Percent in Human Body
Hydrogen
H
1
91
0.14
9.5
Helium
He
2
9
Trace
Trace
Carbon
C
6
0.02
0.03
18.5
Nitrogen
N
7
0.04
Trace
3.3
Oxygen
O
8
0.06
47
65
Sodium
Na
11
Trace
2.8
0.2
Magnesium
Mg
12
Trace
2.1
0.1
Phosphorus
P
15
Trace
0.07
1
Sulfur
S
16
Trace
0.03
0.3
Chlorine
Cl
17
Trace
0.01
0.2
Potassium
K
19
Trace
2.6
0.4
Calcium
Ca
20
Trace
3.6
1.5
Iron
Fe
26
Trace
5
Trace

The percentages are percent by mass of the indicated elements. The composition of the human body is seen to be distinctly different from the abundance of the elements in the Earth's crust. The elements upon which life is based are often summarized by the combination CHONPS, carbon, hydrogen, oxygen, nitrogen, phosphorous and sulfur. Of those, nitrogen is the rarest on the Earth, but is a major component of proteins, the working molecules of life.

Index

Tables

Data Reference
Audesirk & Audesirk
Ch 2, Table 2-1
 
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