The abundance of elements in Earth's crust is shown in tabulated form with the estimated crustal abundance for each

chemical element A chemical element is a chemical substance whose atoms all have the same number of protons. The number of protons is called the atomic number of that element. For example, oxygen has an atomic number of 8: each oxygen atom has 8 protons in its ...

shown as mg/kg, or parts per million (ppm) by

mass Mass is an Intrinsic and extrinsic properties, intrinsic property of a physical body, body. It was traditionally believed to be related to the physical quantity, quantity of matter in a body, until the discovery of the atom and particle physi ...

(10,000 ppm = 1%).

Reservoirs

The Earth's crust is one "reservoir" for measurements of abundance. A reservoir is any large body to be studied as unit, like the ocean, atmosphere, mantle or crust. Different reservoirs may have different relative amounts of each element due to different chemical or mechanical processes involved in the creation of the reservoir.

Difficulties in measurement

Estimates of elemental abundance are difficult because (a) the composition of the upper and lower crust are quite different, and (b) the composition of the continental crust can vary drastically by locality. The composition of the Earth changed after its formation due to loss of volatile compounds, melting and recrystalization, selective loss of some elements to the deep interior, and erosion by water. The lanthanides are especially difficult to measure accurately.

Graphs of abundance vs atomic number

Graphs of abundance against atomic number can reveal patterns relating abundance to

stellar nucleosynthesis In astrophysics, stellar nucleosynthesis is the creation of chemical elements by nuclear fusion reactions within stars. Stellar nucleosynthesis has occurred since the original creation of hydrogen, helium and lithium during the Big Bang. As a ...

and

geochemistry Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the e ...

. The alternation of abundance between even and odd atomic number is known as the Oddo–Harkins rule. The rarest elements in the crust are not the heaviest, but are rather the siderophile elements (iron-loving) in the Goldschmidt classification of elements. These have been depleted by being relocated deeper into the Earth's core; their abundance in

meteoroid A meteoroid ( ) is a small rocky or metallic body in outer space. Meteoroids are distinguished as objects significantly smaller than ''asteroids'', ranging in size from grains to objects up to wide. Objects smaller than meteoroids are classifie ...

s is higher. Tellurium and selenium are concentrated as sulfides in the core and have also been depleted by preaccretional sorting in the nebula that caused them to form volatile hydrogen selenide and hydrogen telluride.Anderson, Don L.; "Chemical Composition of the Mantle", ''Theory of the Earth'', pp. 147–175

List of abundance by element

This table gives the estimated abundance in parts per million by mass of elements in the continental crust; values of the less abundant elements may vary with location by several orders of magnitude."Abundance of Elements in the Earth's Crust and in the Sea", ''CRC Handbook of Chemistry and Physics,'' 97th edition (2016–2017), sec. 14, pg. 17

References

External links

* BookRags
Periodic Table
* ''World Book Encyclopedia''
Exploring Earth
* HyperPhysics, Georgia State University

* Eric Scerri, ''The Periodic Table, Its Story and Its Significance'', Oxford University Press, 2007 * * {{Cite web , title=GERM Reservoir Database -- Reservoir Data Model , url=https://earthref.org/GERMRD/reservoirs/ , access-date=2024-03-22 , website=earthref.org Structure of the Earth Properties of chemical elements Lists of chemical elements Earth's crust