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This article uses the standard notation ISO 80000-2, which supersedes ISO 31-11, for spherical coordinates (other sources may reverse the definitions of θ and φ): . The polar angle is denoted by [,]: it is the angle between the z-axis and the radial vector connecting the origin to the point in question.
Del can also be applied to a vector field with the result being a tensor. The tensor derivative of a vector field v {\displaystyle \mathbf {v} } (in three dimensions) is a 9-term second-rank tensor – that is, a 3×3 matrix – but can be denoted simply as ∇ ⊗ v {\displaystyle \nabla \otimes \mathbf {v} } , where ⊗ {\displaystyle \otimes ...
118 chemical elements have been identified and named officially by IUPAC.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).
In organic chemistry, the acetoxy group (abbr. AcO or OAc; IUPAC name: acetyloxy [1]), is a functional group with the formula −OCOCH 3 and the structure −O−C(=O)−CH 3. As the -oxy suffix implies, it differs from the acetyl group (−C(=O)−CH 3) by the presence of an additional oxygen atom. The name acetoxy is the short form of acetyl-oxy.
IUPAC names can sometimes be simpler than older names, as with ethanol, instead of ethyl alcohol. For relatively simple molecules they can be more easily understood than non-systematic names, which must be learnt or looked over. However, the common or trivial name is often substantially shorter and clearer, and so preferred. These non ...
The main purpose of chemical nomenclature is to disambiguate the spoken or written names of chemical compounds: each name should refer to one compound. Secondarily, each compound should have only one name, although in some cases some alternative names are accepted. Preferably, the name should also represent the structure or chemistry of a compound.
Del (given name), a list of people with the given name or nickname; Del Shannon, stage name of American rock and country singer-songwriter Charles Weedon Westover (1934–1990) Del tha Funkee Homosapien (short for "Delvon"), American hip hop artist; Del Fontaine (1904–1935), Canadian boxer and convicted murderer born Raymond Henry Bousquet
From the English "potash": pot-ash (potassium compound prepared from an alkali extracted in a pot from the ash of burnt wood or tree leaves). Potash is a calque of Dutch potaschen, which means "pot ashes". [19] · Symbol K is for the Latin name kalium, from Arabic القلي (al qalīy), which means "calcined ashes". Calcium (Ca) 20 χάλιξ ...