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A mnemonic is a memory aid used to improve long-term memory and make the process of consolidation easier. Many chemistry aspects, rules, names of compounds, sequences of elements, their reactivity, etc., can be easily and efficiently memorized with the help of mnemonics.
Zn 3 As 2 has a room-temperature tetragonal form that converts to a different tetragonal phase at 190 °C and to a third phase at 651 °C. [3] In the room-temperature form, the zinc atoms are tetrahedrally coordinated and the arsenic atoms are surrounded by six zinc atoms at the vertices of a distorted cube.
Zinc chemistry resembles that of the late first-row transition metals, nickel and copper, [53] as well as certain main group elements. Almost all zinc compounds have the element in the +2 oxidation state. [54] When Zn 2+ compounds form, the outer shell s electrons are lost, yielding a bare zinc ion with the electronic configuration [Ar]3d 10. [55]
Zn 2+ is a class A acceptor in the classification of Ahrland, Chatt and Davies, [16] and so forms stronger complexes with the first-row donor atoms oxygen or nitrogen than with second-row sulfur or phosphorus. In terms of HSAB theory Zn 2+ is a hard acid. In aqueous solution an octahedral complex, [Zn(H 2 O) 6] 2+ is the predominant species. [17]
The value 2S + 1 written in the term symbol is the spin multiplicity, which is the number of possible values of the spin magnetic quantum number M S for a given spin S. J is the total angular momentum quantum number for the atom's electrons. J has a value in the range from |L − S| to L + S.
Relative atomic mass (symbol: A r; sometimes abbreviated RAM or r.a.m.), also known by the deprecated synonym atomic weight, is a dimensionless physical quantity defined as the ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass constant.
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
Note that the especially high molar values, as for paraffin, gasoline, water and ammonia, result from calculating specific heats in terms of moles of molecules. If specific heat is expressed per mole of atoms for these substances, none of the constant-volume values exceed, to any large extent, the theoretical Dulong–Petit limit of 25 J⋅mol ...