 |
3.1.3 Abundances of the elements
This table gives an indication of the abundances of the
elements in nature. Parts per million, by mass, are denoted by
‘ppm’, whereas abundances stated to be in ‘atoms’ are
numbers of atoms per 106 atoms of silicon. The values for sea water
and for crustal rocks are from Turekian (1970). Those for stony meteorites are
mean values for the commoner varieties of ordinary chondrites taken from Mason
(1971) and those for iron meteorites are from Brown (1949) (major elements),
from Smales et al. (1968) (trace elements) or from Mason (1971). The
values for trace elements in iron meteorites are exceedingly variable and the
results given are mean values for median octahedrites. Values for the Sun and
Solar System are taken from Grevesse and Anders (1988), except for the solar
iron abundance taken from Holweger et al. (1991). The accuracy of the
solar abundances varies between ± 10% and a factor of 2 or worse, the
latter cases being marked with a colon. The Solar System abundances, based
mainly on carbonaceous chondrite meteorites, are generally accurate to ±
10% or better, and they refer
to the time of formation of the Solar System allowing for radioactive decay of
uranium and thorium. Solar System abundances based on other sources (solar or
nearby galactic emission nebulae) are shown in parentheses.
Abundances given for some elements in the Sun are
different from those given for the Solar System and in particular this applies
to lithium which has been largely destroyed in the Sun owing to thermonuclear
reactions during the Sun's lifetime. Other differences between abundances for
the Sun and for the Solar System are mainly due to uncertainties in the
determinations, especially for the Sun.
Solar System abundances are quite similar to those found
in most stars and interstellar material in our neighbourhood and in
corresponding parts of other galaxies where, however, minor variations (within
a factor of 3 or so either way) may occur in the relative amounts of hydrogen
and helium, on the one hand, and carbon and heavier elements on the other. This
reflects the fact that hydrogen and the bulk of helium are thought to be relics
from the ‘Big Bang’, whereas heavier elements (and a minority of
the helium) result from nuclear reactions in stars or in the interstellar
medium. Carbon and heavier elements tend to be relatively more abundant in the
central regions of large galaxies (such as our own) than in their outer parts
or in small galaxies; in stars belonging to the outer spheroidal halo of our
Galaxy carbon and heavier elements may be deficient by factors of up to 1 000
or more (relative to hydrogen and helium) when compared to Solar System values,
and among these elements, carbon, nitrogen, iron and elements such as barium
(resulting from the ‘slow’ neutron capture or s-process in the
progenitor stars) can be deficient by larger factors than oxygen, magnesium and
other ‘α-particle’ elements
synthesised in massive stars which undergo supernova explosions after 10
million years or so. Peculiar over- and under-abundances of various elements
can also be found in some highly evolved stars as a result of internal nuclear
reactions, and in the surface layers of certain stars where diffusive
separation of elements seems to have occurred.
The composition of the atmosphere is from Kuiper (1949)
with corrections from Glueckauf and Kitt (1956).
References
H. Brown (1949) Rev. Mod. Phys., 21, 625.
Glueckauf
and Kitt (1956) Proc. Roy. Soc. A, 234, 557.
N.
Grevesse and E. Anders (1988) in Cosmic Abundances of Matter (ed. J.
Waddington), Amer. Inst. Phys.,
New York, p. 1.
H. Holweger, A. Bard, A. Kock and M. Kock (1991) Astron.
Astrophys., 249, 545.
G. P. Kuiper (ed.) (1949) The
Atmospheres of the Earth and Planets, Univ. of Chicago Press.
B. Mason
(1971) Handbook of Elemental Abundances in Meteorites, Gordon and
Breach, New York.
A. A. Smales, D. Mapper and K. F. Fouche (1968) in
Origin and Distribution of the Elements (ed. L. H. Ahrens),
Pergamon Press, London, pp. 329–344.
K. K.
Turekian (1970) in McGraw-Hill Encyclopedia of Science and Technology,
4, 627.
Abundances
|
At.
No. |
Element |
|
|
Meteorites |
Sun
atoms |
Solar
system
atoms |
|
|
|
|
|
|
|
|
|
|
|
|
|
1 |
H |
1.1 × 108 |
— |
— |
— |
2.8 × 1010 |
(2.8 × 1010) |
|
2 |
He |
0.007 2 |
— |
— |
— |
2.7 × 109 |
(2.7 × 109) |
|
3 |
Li |
1.7 × 102 |
20 |
1.7 |
— |
0.4 |
57 |
|
4 |
Be |
0.000 6 |
2.0 |
0.040 |
— |
0.4 |
0.7 |
|
5 |
B |
4.4 × 103 |
7.0 |
2.1 |
— |
11 |
21 |
|
|
|
|
|
|
|
|
|
|
6 |
C |
2.8 × 104 |
— |
1.0 × 103 |
1.1 × 103 |
1.0 × 107 |
(1.0 × 107) |
|
7 |
N |
1.6 × 104 |
20 |
61 |
33 |
3.1 × 106 |
(3.1 × 106) |
|
8 |
O |
8.8 × 108 |
3.7 × 105 |
3.7 × 105 |
— |
2.4 × 107 |
(2.4 × 107) |
|
9 |
F |
1.3 × 103 |
4.6 × 102 |
1.2 × 102 |
— |
103: |
8.5 × 102 |
|
10 |
Ne |
0.12 |
— |
— |
— |
3 × 106 |
(3 × 106) |
|
|
|
|
|
|
|
|
|
|
11 |
Na |
1.1 × 107 |
2.3 × 104 |
6.2 × 103 |
— |
6.0 × 104 |
5.7 × 104 |
|
12 |
Mg |
1.3 × 106 |
2.8 × 104 |
1.5 × 105 |
3.2 × 102 |
1.0 × 106 |
1.1 × 106 |
|
13 |
Al |
1 |
8.0 × 104 |
1.0 × 104 |
40 |
8.3 × 104 |
8.5 × 104 |
|
14 |
Si |
2.9 × 103 |
2.7 × 105 |
1.8 × 105 |
40 |
1.0 × 106 |
1.0 × 106 |
|
15 |
P |
88 |
1.0 × 103 |
1.1 × 103 |
2.2 × 103 |
8 × 103 |
1.0 × 104 |
|
|
|
|
|
|
|
|
|
|
16 |
S |
9.0 × 105 |
3.0 × 102 |
2.1 × 104 |
3.6 × 102 |
4.5 × 105 |
5.2 × 105 |
|
17 |
Cl |
1.9 × 107 |
1.9 × 102 |
80 |
— |
9 × 103: |
5.2 × 103 |
|
18 |
Ar |
4.5 × 102 |
— |
— |
— |
(1.0 × 105) |
(1.0 × 105) |
|
19 |
K |
3.9 × 105 |
1.7 × 104 |
8.8 × 102 |
— |
3.7 × 103 |
3.8 × 103 |
|
20 |
Ca |
4.1 × 105 |
5.1 × 104 |
1.2 × 104 |
5.0 × 102 |
6.4 × 104 |
6.1 × 104 |
|
|
|
|
|
|
|
|
|
|
21 |
Sc |
< 0.004 |
22 |
7.6 |
— |
35 |
34 |
|
22 |
Ti |
1 |
8.6 × 103 |
6.4 × 102 |
1.0 × 102 |
2.7 × 103 |
2.4 × 103 |
|
23 |
V |
1.9 |
1.7 × 102 |
63 |
6 |
2.8 × 102 |
2.9 × 102 |
|
24 |
Cr |
0.2 |
96 |
3.6 × 103 |
15 |
1.3 × 104 |
1.3 × 104 |
|
25 |
Mn |
1.9 |
1.0 × 103 |
2.3 × 103 |
3.0 × 102 |
6.9 × 103 |
9.5 × 103 |
|
|
|
|
|
|
|
|
|
|
26 |
Fe |
3.4 |
5.8 × 104 |
2.5 × 105 |
9.1 × 105 |
9.0 × 105 |
9.0 × 105 |
|
27 |
Co |
0.39 |
28 |
7.0 × 102 |
6.3 × 103 |
2.3 × 103 |
2.3 × 103 |
|
28 |
Ni |
6.6 |
72 |
1.5 × 104 |
6.7 × 104 |
5.0 × 104 |
5.0 × 104 |
|
29 |
Cu |
23 |
58 |
90 |
1.3 × 102 |
4.5 × 102 |
5.2 × 102 |
|
30 |
Zn |
11 |
82 |
54 |
28 |
1.1 × 103 |
1.3 × 103 |
|
|
|
|
|
|
|
|
|
|
31 |
Ga |
0.03 |
17 |
5.1 |
80 |
21 |
38 |
|
32 |
Ge |
0.06 |
1.3 |
10 |
37 |
72 |
1.2 × 102 |
|
33 |
As |
2.6 |
2.0 |
1.8 |
11 |
— |
6.6 |
|
34 |
Se |
0.090 |
0.05 |
8.0 |
3 |
— |
63 |
|
35 |
Br |
6.7 × 104 |
4.0 |
0.4 |
1 |
— |
12 |
|
|
|
|
|
|
|
|
|
|
36 |
Kr |
0.21 |
— |
— |
— |
— |
48 |
|
37 |
Rb |
1.2 × 102 |
70 |
4.0 |
— |
11 |
7.0 |
|
38 |
Sr |
8.1 × 103 |
4.5 × 102 |
10.0 |
— |
22 |
24 |
|
39 |
Y |
0.001 3 |
0.35 |
2.2 |
— |
4.9 |
4.6 |
|
40 |
Zr |
0.026 |
1.4 × 102 |
10 |
8 |
11.2 |
11.4 |
|
|
|
|
|
|
|
|
|
|
41 |
Nb |
0.015 |
20 |
0.1 |
0.2 |
0.7 |
0.70 |
|
42 |
Mo |
10 |
1.2 |
1.5 |
7.3 |
2.3 |
2.6 |
|
43 |
Tc |
Unstable with short period |
|
|
|
|
|
44 |
Ru |
— |
— |
0.9 |
11 |
1.9 |
1.9 |
|
45 |
Rh |
— |
— |
0.23 |
4.1 |
0.4 |
0.34 |
|
|
|
|
|
|
|
|
|
|
46 |
Pd |
— |
0.003 |
0.84 |
3.8 |
1.4 |
1.4 |
|
47 |
Ag |
0.28 |
0.08 |
0.085 |
0.035 |
0.2: |
0.49 |
|
48 |
Cd |
0.11 |
0.18 |
0.06 |
0.02 |
2.0 |
1.6 |
|
49 |
In |
— |
0.2 |
0.004 |
0.010 |
1.3: |
0.19 |
|
50 |
Sn |
0.81 |
1.5 |
0.65 |
2 |
3: |
3.9 |
|
|
|
|
|
|
|
|
|
|
51 |
Sb |
0.33 |
0.2 |
0.10 |
0.34 |
0.3: |
0.31 |
|
52 |
Te |
— |
— |
1.7 |
— |
— |
4.9 |
|
53 |
I |
64 |
0.5 |
0.036 |
0.6 |
— |
0.9 |
|
54 |
Xe |
0.047 |
— |
— |
— |
— |
4.8 |
|
55 |
Cs |
0.30 |
1.6 |
0.08 |
— |
— |
0.37 |
|
|
|
|
|
|
|
|
|
|
56 |
Ba |
21 |
3.8 × 102 |
3.5 |
— |
3.8 |
4.5 |
|
57 |
La |
0.003 4 |
50 |
0.32 |
— |
0.5 |
0.44 |
|
58 |
Ce |
0.001 2 |
83 |
0.86 |
— |
1.0 |
1.1 |
|
59 |
Pr |
0.000
64 |
13 |
0.12 |
— |
0.14 |
0.17 |
|
60 |
Nd |
0.002 8 |
44 |
0.59 |
— |
0.9 |
0.83 |
|
|
|
|
|
|
|
|
|
|
61 |
Pm |
Unstable with short period |
|
|
|
|
|
62 |
Sm |
0.000
45 |
7.7 |
0.19 |
— |
0.3 |
0.26 |
|
63 |
Eu |
0.000
13 |
2.2 |
0.07 |
— |
0.09 |
0.097 |
|
64 |
Gd |
0.000
70 |
6.3 |
0.28 |
— |
0.37 |
0.33 |
|
65 |
Tb |
0.001 4 |
1.0 |
0.048 |
— |
0.02: |
0.060 |
|
|
|
|
|
|
|
|
|
|
66 |
Dy |
0.000
91 |
8.5 |
0.31 |
— |
0.35 |
0.40 |
|
67 |
Ho |
0.000
22 |
1.6 |
0.07 |
— |
0.05: |
0.089 |
|
68 |
Er |
0.008 7 |
3.6 |
0.20 |
— |
0.24 |
0.25 |
|
69 |
Tm |
0.000
17 |
0.52 |
0.03 |
— |
0.03: |
0.038 |
|
70 |
Yb |
0.000
82 |
3.4 |
0.19 |
— |
0.34 |
0.25 |
|
|
|
|
|
|
|
|
|
|
71 |
Lu |
0.000 15 |
0.8 |
0.033 |
— |
0.15: |
0.037 |
|
72 |
Hf |
<0.008 |
4 |
0.24 |
— |
0.21 |
0.15 |
|
73 |
Ta |
<0.002 5 |
2.4 |
0.022 |
0.06 |
— |
0.038 |
|
74 |
W |
<0.001 |
1.0 |
0.15 |
8.1 |
0.36: |
0.13 |
|
75 |
Re |
— |
0.000 4 |
0.058 |
0.85 |
— |
0.05 |
|
|
|
|
|
|
|
|
|
|
76 |
Os |
— |
0.000 2 |
0.77 |
7.6 |
0.8 |
0.67 |
|
77 |
Ir |
— |
0.000 2 |
0.64 |
3.0 |
0.6 |
0.66 |
|
78 |
Pt |
— |
— |
1.1 |
19 |
1.8: |
1.34 |
|
79 |
Au |
0.011 |
0.002 |
0.20 |
1.8 |
0.3: |
0.19 |
|
80 |
Hg |
0.15 |
0.02 |
0.13 |
— |
— |
0.34 |
|
|
|
|
|
|
|
|
|
|
81 |
Tl |
— |
0.47 |
0.003 |
— |
0.2: |
0.19 |
|
82 |
Pb |
0.03 |
10 |
0.30 |
60 |
2.0 |
3.1 |
|
83 |
Bi |
0.02 |
0.004 |
0.012 |
0.5 |
— |
0.14 |
|
84–89 |
Po–Ac |
Unstable with short period |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
90 |
Th |
0.001 5 |
5.8 |
0.044 |
0.04 |
0.05 |
0.045 |
|
91 |
Pa |
Unstable with short period |
| |
