Search results
Results From The WOW.Com Content Network
White phosphorus, yellow phosphorus, or simply tetraphosphorus (P 4) is an allotrope of phosphorus.It is a translucent waxy solid that quickly yellows in light (due to its photochemical conversion into red phosphorus), [2] and impure white phosphorus is for this reason called yellow phosphorus.
In a tetrahedral molecular geometry, a central atom is located at the center with four substituents that are located at the corners of a tetrahedron. The bond angles are arccos (− 1 / 3 ) = 109.4712206...° ≈ 109.5° when all four substituents are the same, as in methane ( CH 4 ) [ 1 ] [ 2 ] as well as its heavier analogues .
Phosphonium ion Structure of PH + 4, the parent phosphonium cation. In chemistry, the term phosphonium (more obscurely: phosphinium) describes polyatomic cations with the chemical formula PR + 4 (where R is a hydrogen or an alkyl, aryl, or halide group). These cations have tetrahedral structures.
It would appear that violet phosphorus is a polymer of high relative molecular mass, which on heating breaks down into P 2 molecules. On cooling, these would normally dimerize to give P 4 molecules (i.e. white phosphorus) but, in a vacuum , they link up again to form the polymeric violet allotrope.
PF 5 is a colourless gas and the molecules have trigonal bipyramidal geometry. PCl 5 is a colourless solid which has an ionic formulation of PCl 4 + PCl 6 −, but adopts the trigonal bipyramidal geometry when molten or in the vapour phase. [17] PBr 5 is an unstable solid formulated as PBr 4 + Br − and PI 5 is not known. [17]
Theories of chemical structure were first developed by August Kekulé, Archibald Scott Couper, and Aleksandr Butlerov, among others, from about 1858. [4] These theories were first to state that chemical compounds are not a random cluster of atoms and functional groups, but rather had a definite order defined by the valency of the atoms composing the molecule, giving the molecules a three ...
A central atom is defined in this theory as an atom which is bonded to two or more other atoms, while a terminal atom is bonded to only one other atom. [ 1 ] : 398 For example in the molecule methyl isocyanate (H 3 C-N=C=O), the two carbons and one nitrogen are central atoms, and the three hydrogens and one oxygen are terminal atoms.
Keggin structure James F. Keggin, the discoverer of the Keggin Structure. Keggin structure. The Keggin structure is the best known structural form for heteropoly acids.It is the structural form of α-Keggin anions, which have a general formula of [XM 12 O 40] n −, where X is the heteroatom (most commonly are pentavalent phosphorus P V, tetravalent silicon Si IV, or trivalent boron B III), M ...