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Contributing structures of the carbonate ion. In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures (or forms, [1] also variously known as resonance structures or canonical structures) into a resonance hybrid (or hybrid structure) in valence bond theory.
The mineral malachite is a typical example of a basic carbonate. The formula, Cu 2 CO 3 (OH) 2 shows that it is halfway between copper carbonate and copper hydroxide. Indeed, in the past the formula was written as CuCO 3 ·Cu(OH) 2. The crystal structure is made up of copper, carbonate and hydroxide ions. [37] The mineral atacamite is an ...
Another class of oxonium ions encountered in organic chemistry is the oxocarbenium ions, obtained by protonation or alkylation of a carbonyl group e.g. R−C= + −R′ which forms a resonance structure with the fully-fledged carbocation R− + −O−R′ and is therefore especially stable:
In chemistry, the mesomeric effect (or resonance effect) is a property of substituents or functional groups in a chemical compound.It is defined as the polarity produced in the molecule by the interaction of two pi bonds or between a pi bond and lone pair of electrons present on an adjacent atom. [1]
This structure can also be considered to be a distorted hcp lattice with the nearest neighbours in the same plane being approx 16% farther away [18] β-Po: A i: Rhombohedral: R 3 m (No. 166) 1 (rh.) 3 (hex.) Identical symmetry to the α-Hg structure, distinguished based on details about the basis vectors of its unit cell. γ-Se: A8: Hexagonal ...
In inorganic chemistry, mineral hydration is a reaction which adds water to the crystal structure of a mineral, usually creating a new mineral, commonly called a hydrate. In geological terms, the process of mineral hydration is known as retrograde alteration and is a process occurring in retrograde metamorphism .
Size: 8.4 × 5.2 × 4.1 cm. Layered double hydroxides (LDH) are a class of ionic solids characterized by a layered structure with the generic layer sequence [AcB Z AcB] n, where c represents layers of metal cations, A and B are layers of hydroxide (OH −) anions, and Z are layers of other anions and neutral molecules (such as water). [1]
Mineral symbols (text abbreviations) are used to abbreviate mineral groups, subgroups, and species, just as lettered symbols are used for the chemical elements. The first set of commonly used mineral symbols was published in 1983 and covered the common rock-forming minerals using 192 two- or three-lettered symbols. [ 1 ]