BORON NATURAL ABUNDANCE PLUS

Cosmological observations suggest that only 4.6% of the universe's energy (including the mass contributed by energy, E = mc 2 ⇔ m = E / c 2) comprises the visible baryonic matter that constitutes stars, planets, and living beings. The elements – that is, ordinary ( baryonic) matter made of protons, neutrons, and electrons, are only a small part of the content of the Universe. See also: Stellar population, Cosmochemistry, and Astrochemistry Ten most common elements in the Milky Way Galaxy estimated spectroscopically Z The abundance of elements in specialized environments, such as atmospheres, or oceans, or the human body, are primarily a product of chemical interactions with the medium in which they reside. Lighter silicates of aluminium are found in the crust, with more magnesium silicate in the mantle, while metallic iron and nickel compose the core.

BORON NATURAL ABUNDANCE PLUS

The crust, mantle, and core of the Earth show evidence of chemical segregation plus some sequestration by density. Due to solar heating, the elements of Earth and the inner rocky planets of the Solar System have undergone an additional depletion of volatile hydrogen, helium, neon, nitrogen, and carbon (which volatilizes as methane). The abundance of elements in the Sun and outer planets is similar to that in the universe. Also, elements with even atomic numbers are generally more common than their neighbors in the periodic table, due to favorable energetics of formation. Elements of higher atomic number than iron (element 26) become progressively rarer in the universe, because they increasingly absorb stellar energy in their production. The elements from carbon to iron are relatively more abundant in the universe because of the ease of making them in supernova nucleosynthesis. Lithium, beryllium, and boron, despite their low atomic number, are rare because, although they are produced by nuclear fusion, they are destroyed by other reactions in the stars. Remaining elements, making up only about 2% of the universe, were largely produced by supernovae and certain red giant stars. The abundance of chemical elements in the universe is dominated by the large amounts of hydrogen and helium which were produced in the Big Bang. Changing the given environment to Jupiter's outer atmosphere, where hydrogen is diatomic while helium is not, changes the molecular mole fraction (fraction of total gas molecules), as well as the fraction of atmosphere by volume, of hydrogen to about 86%, and of helium to 13%. As another example, looking at the mass fraction abundance of hydrogen and helium in both the Universe as a whole and in the atmospheres of gas-giant planets such as Jupiter, it is 74% for hydrogen and 23–25% for helium while the (atomic) mole fraction for hydrogen is 92%, and for helium is 8%, in these environments. However, the mole fraction is about 33% because only 1 atom of 3 in water, H 2O, is oxygen. Most abundance values in this article are given as mass fractions.įor example, the abundance of oxygen in pure water can be measured in two ways: the mass fraction is about 89%, because that is the fraction of water's mass which is oxygen. Volume fraction is a common abundance measure in mixed gases such as planetary atmospheres, and is similar in value to molecular mole fraction for gas mixtures at relatively low densities and pressures, and ideal gas mixtures. 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. The abundance of the chemical elements is a measure of the occurrence of the chemical elements relative to all other elements in a given environment.

Abundance at scales including the Universe, the Earth and the human body

Boron natural abundance