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Bioconcentration. In aquatic toxicology, bioconcentration is the accumulation of a water-borne chemical substance in an organism exposed to the water. [1][2] There are several ways in which to measure and assess bioaccumulation and bioconcentration. These include: octanol-water partition coefficients (K OW), bioconcentration factors (BCF ...
Bromochlorodifluoromethane (BCF), also referred to by the code numbers Halon 1211 and Freon 12B1, is a haloalkane with the chemical formula C F 2 Cl Br. It is used for fire suppression, especially for expensive equipment or items that could be damaged by the residue from other types of extinguishers. [ 1 ]
Tris (pentafluorophenyl)borane, sometimes referred to as "BCF", is the chemical compound (C6F5)3B. It is a white, volatile solid. The molecule consists of three pentafluorophenyl groups attached in a "paddle-wheel" manner to a central boron atom; the BC3 core is planar. It has been described as the “ideal Lewis acid ” because of its high ...
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...
In physical cosmology, the age of the universe is the time elapsed since the Big Bang.Astronomers have derived two different measurements of the age of the universe: [1] a measurement based on direct observations of an early state of the universe, which indicate an age of 13.787 ± 0.020 billion years as interpreted with the Lambda-CDM concordance model as of 2021; [2] and a measurement based ...
U+12400–U+1247F Cuneiform Numbers and Punctuation. U+12480–U+1254F Early Dynastic Cuneiform. The sample glyphs in the chart file published by the Unicode Consortium [3] show the characters in their Classical Sumerian form (Early Dynastic period, mid 3rd millennium BCE). The characters as written during the 2nd and 1st millennia BCE, the era ...
Copy number variation is a type of structural variation: specifically, it is a type of duplication or deletion event that affects a considerable number of base pairs. [2] Approximately two-thirds of the entire human genome may be composed of repeats [3] and 4.8–9.5% of the human genome can be classified as copy number variations. [4]
On scientific calculators, it is usually known as "SCI" display mode. In scientific notation, nonzero numbers are written in the form. or m times ten raised to the power of n, where n is an integer, and the coefficient m is a nonzero real number (usually between 1 and 10 in absolute value, and nearly always written as a terminating decimal).