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The abundance of elements in Earth's crust is shown in tabulated form with the estimated crustal abundance for each chemical element shown as mg/kg, or parts per million (ppm) by mass (10,000 ppm = 1%).
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.
As I Ching and Feng Shui described, Earth is the center to which all movements tend to go to or come from, even if temporarily, that is to say, as with all of the elements or phases it can polarize with any of the other movements-elements: Fire, Water, Wood and Metal. These four types of Earth are Earth-of-water (Wet/Cold Earth), Earth-of-Fire ...
Earth is rounded into an ellipsoid with a circumference of about 40,000 km. It is the densest planet in the Solar System. Of the four rocky planets, it is the largest and most massive. Earth is about eight light-minutes away from the Sun and orbits it, taking a year (about 365.25 days) to complete one revolution.
The abundance in the Earth's crust is approximately 16.9 ppm. It is the 34th most abundant element in the crust. [56] This is comparable to the crustal abundances of lead, cobalt, and niobium. Yet unlike these elements, gallium does not form its own ore deposits with concentrations of > 0.1 wt.% in ore.
While iron is the most abundant element on Earth, most of this iron is concentrated in the inner and outer cores. [43] [44] The fraction of iron that is in Earth's crust only amounts to about 5% of the overall mass of the crust and is thus only the fourth most abundant element in that layer (after oxygen, silicon, and aluminium). [45]
In summary, the mass of Earth's atmosphere is distributed approximately as follows: [42] 50% is below 5.6 km (18,000 ft), 90% is below 16 km (52,000 ft), 99.99997% is below 100 km (62 mi; 330,000 ft), the Kármán line. By international convention, this marks the beginning of space where human travelers are considered astronauts.
Thus, about 99% of Earth's internal heat loss at the surface is by conduction through the crust, and mantle convection is the dominant control on heat transport from deep within the Earth. Most of the heat flow from the thicker continental crust is attributed to internal radiogenic sources; in contrast the thinner oceanic crust has only 2% ...