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The abundance of the chemical elements is a measure of the occurrences of the chemical elements relative to all other elements in a given environment. Abundance is measured in one of three ways: by mass fraction (in commercial contexts often called weight fraction), by mole fraction (fraction of atoms by numerical count, or sometimes fraction of molecules in gases), or by volume fraction.
Estimated abundance of the elements in the continental crust (C1) and in seawater near the surface (W1). The median values of reported measurements are given. Concentrations of the less abundant elements may vary with location by several orders of magnitude.
Silicon is a bioessential element and is one of the most abundant elements on Earth. [61] [62] The silica cycle has significant overlap with the carbon cycle (see the carbonate–silicate cycle) and plays an important role in the sequestration of carbon through continental weathering, biogenic export and burial as oozes on geologic timescales. [63]
Iron is the most abundant element by mass in the Earth, but most of it is locked up in the Earth’s core, 1,800 miles beneath our feet, Wade said. Despite this, life forms rely on iron for survival.
Although it is rare on Earth, helium is the second most abundant element in the known Universe, constituting 23% of its baryonic mass. Only hydrogen is more abundant. [28] The vast majority of helium was formed by Big Bang nucleosynthesis one to three minutes after the Big Bang. As such, measurements of its abundance contribute to cosmological ...
Oxygen is the third most abundant chemical element in the universe, after hydrogen and helium. [68] About 0.9% of the Sun's mass is oxygen. [19] Oxygen constitutes 49.2% of the Earth's crust by mass [69] as part of oxide compounds such as silicon dioxide and is the most abundant element by mass in the Earth's crust.
The atmosphere of Earth is composed of a layer of gas mixture that surrounds the Earth's planetary surface (both lands and oceans), known collectively as air, with variable quantities of suspended aerosols and particulates (which create weather features such as clouds and hazes), all retained by Earth's gravity.
Are You Smarter Than a 5th Grader?: Social Studies — aka History and Gossip . Where does the President of the United States live? Answer: The White House