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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.
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]
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.
The block names (s, p, d, and f) are derived from the spectroscopic notation for the value of an electron's azimuthal quantum number: sharp (0), principal (1), diffuse (2), and fundamental (3). Succeeding notations proceed in alphabetical order, as g, h, etc., though elements that would belong in such blocks have not yet been found.
It includes zinc (Zn), cadmium (Cd), mercury (Hg), [2] [3] [4] and copernicium (Cn). [5] Formerly this group was named IIB (pronounced as "group two B", as the "II" is a Roman numeral) by CAS and old IUPAC system. [note 1] The three group 12 elements that occur naturally are zinc, cadmium and mercury.
This is a list of chemical elements and their atomic properties, ordered by atomic number (Z).. Since valence electrons are not clearly defined for the d-block and f-block elements, there not being a clear point at which further ionisation becomes unprofitable, a purely formal definition as number of electrons in the outermost shell has been used.
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.