Bivalent atom

The metallic form of tin, white tin, consists largely of the bivalent atoms SnB, which have a metallic orbital. In white tin each atom has co-ordination number 6, and the bonds resonate among the alternative positions. It is the energy of this... 

Symbol = O—Bivalent—Atomic weight = 16 molecular weight = 32—Sp. gr.— 1.10563 A calculated = 1.1088) 15.95 H sp. gr. of liquid = 0.9787—One litre weighs 1.4300 grams = 16 criths—100 cubic inches weigh 34.27 grains—Name derived from ofvf = acid, and yewaa = I produce—Discovered by Mayow in 1674 re-discovered by Priestley in 1774. 

Although square-planar configuration is customarily considered classical for v/c-dioximate of nickel(II), attempts have been made repeatedly over the years for preparing the above complexes in other configurations also. By employing weakly polar solvents and some other variations, success has been claimed in the preparation of mono(dioxime) complexes of nickel(II). The dichloro-bis(l,2-cyclohexanedione dioximato)nickel(II) has been shown to have an octahedral vie structure. Examples of tris(dioxime) complexes of transition metals in generaP and of bivalent atoms - in particular are rare and structural details of only a tris(dioxime) complex of cobalt(III) are known. In a more recent publication, the crystal structure of tris(l,2-cyclohexanedione dioximo)nickel(II) sulfate dihydrate has been elucidated. 

Composition.—Various views have been adopted respecting the constitution of this body it may, however, be regarded as the ammonium chloride, in which two atoms of hydrogen are replaced by a bivalent atom of mercury its formula then becomes NH2HgCl. 

Lossen spoke of an atom in direct union with another as present in a zone of union (Bindungszone). He assumed that hydrogen and (incorrectly) halogens and thallium are always univalent the valencies of other elements may vary up to a maximum (probably 6). In CH4 four univalent atoms are in direct union with an atom of carbon in C(OC2Hg)4 four bivalent atoms (oxygen) are in the same zone of union in C(CH3)4 quadrivalent (C) in /CHs... 

In the general formula of the alumino-silicates, MAlSia 02a +2 5 both the type of cations M and the parameter x can vary considerably. Furthermore, the Si02 content can be replaced by AIPO4 to some extent. Finally, limited substitution of A1 in the aluminate component MAIO2 by other small trivalent or even bivalent atoms has also been reported. 

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