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2,4-Dichlorophenoxyacetic acid is an organic compound with the chemical formula Cl 2 C 6 H 3 OCH 2 CO 2 H.It is usually referred to by its ISO common name 2,4-D. [4] It is a systemic herbicide that kills most broadleaf weeds by causing uncontrolled growth, but most grasses such as cereals, lawn turf, and grassland are relatively unaffected.
Europium compounds (2 C, 4 P) F. Fluorine compounds (4 C, 41 P) ... Pages in category "Chemical compounds by element" The following 75 pages are in this category, out ...
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 ...
While the full work of the unit remained secret, certain discoveries were developed for commercial use after the war, including the 2,4-D compound. [15] When 2,4-D was commercially released in 1946, it became the first successful selective herbicide, triggering a worldwide revolution in agricultural output.
A distinct chemical symbol is used for convenience because of the isotope's common use in various scientific processes. Also, its large mass difference with protium (1 H) confers non-negligible chemical differences with 1 H compounds. Deuterium has a mass of 2.014 102 Da, about twice the mean hydrogen atomic weight of 1.007 947 Da, or twice ...
[1] [2] Chemical substances may take the form of a single element or chemical compounds. If two or more chemical substances can be combined without reacting, they may form a chemical mixture. [3] If a mixture is separated to isolate one chemical substance to a desired degree, the resulting substance is said to be chemically pure. [4]
As a special case, the three naturally occurring isotopes of hydrogen are often specified as H for 1 H , D for 2 H , and T for 3 H . This convention is easier to use in chemical equations, replacing the need to write out the mass number each time. Thus, the formula for heavy water may be written D 2 O instead of 2 H 2 O.
[16] [17] [18] A molecule may be homonuclear, that is, it consists of atoms of one chemical element, as with two atoms in the oxygen molecule (O 2); or it may be heteronuclear, a chemical compound composed of more than one element, as with water (two hydrogen atoms and one oxygen atom; H 2 O). A molecule is the smallest unit of a substance that ...