Electropositive constituent

Placement of Atoms in a Formula. The electropositive constituent (cation) is placed first in a formula. If the compound contains more than one electropositive or more than one electronegative constituent, the sequence within each class should be in alphabetical order of their symbols. 

Ternary compounds are also named by citing the more electropositive constituent first. The various oxidation states of the more electropositive element are designated by a system of prefixes and terminations added to a stem characteristic of the element, except in the case of coordination compounds (qv). Examples are as follows (see Chlorine oxygen acids and salts) ... 

For a discussion on the trends of lattice parameter and volume changes consequent on disordering some types of structure see Bhatia and Cahn (2005). They observed that, when the more electropositive constituent of the alloy is a simple metal, a strong correlation may be observed between the volume increase on disordering and the formation volume of the ordered alloy. 

The name is derived by combining the names of the electropositive constituent(s) with those of the electronegative constituent(s), suitably modified by any necessary... 

The name of the electropositive constituent is simply the unmodified element name, the name of a polyatomic cation or an accepted group name, as appropriate. 

If there is more than one electropositive constituent, the names should be spaced and cited in alphabetical order of the initial letters, or of the second letters if the first letters are the same. Multiplicative prefixes are ignored for purposes of ordering. 

Hydrogen is an exception. It is always cited last among the electropositive constituents and is separated from the following anion names by a space unless it is known to be bound to the anion. In languages other than English, different ordering may apply. In the examples, the letters defining the order are in bold face for clarity. This should not be extended to normal practice. 

Electronegativities and citation order. In a formula the order of citation of symbols is based upon relative electronegativities, the more electropositive constituents) being cited first. Iq the formulae of Br0nsted acids, acid hydrogen is considered to be an electropositive constituent and immediately precedes the anionic constituents. 

Electropositive condiments. The name of a monoatomic electropositive constituent is simply the unmodified element name. A polyatomic constituent assumes the usual cation name, but certain well established radical names (particularly for oxygen-containing species such as nitrosyl and phosphoryl) are still allowed for specific cases... 

The nomenclature pattern established in binary nomenclature is also used to indicate the composition of more complex entities, including ionic coordination compounds. Electropositive constituents are cited in alphabetical order before the electronegative constituents, which are also cited in alphabetical order. For examples see Table 2. 

The elements are divided into two classes, metals and non-metals. Chemically the properties of the metals are as different from those of the non-metals as physically, for the metals form the electropositive constituents of compounds, whereas the non-metals form the electronegative constituents. 

The first formula in Example 8 was arrived at by considering K and Cu to be electropositive constituents and Sb to be electronegative, the second by considering K to be electropositive and Cu and Sb to be electronegative. No structural information is conveyed by these formulae. The formula in Example 9, on the other hand, implies the presence of the coordination entity [CuSb2]5-. 

The stoichiometric name of the compound is then formed by combining the name of the electropositive constituent, cited first, with that of the electronegative constituent, both suitably qualified by any necessary multiplicative prefixes ( mono , di , tri , tetra , penta , etc., given in Table IV). The multiplicative prefixes precede the names they multiply, and are joined directly to them without spaces or hyphens. The final vowels of multiplicative prefixes should not be elided (although monoxide , rather than monooxide , is an allowed exception because of general usage). The two parts of the name are separated by a space in English. 

The names of the electropositive constituents precede those of the electronegative constituents in the overall name. The order of citation is alphabetical within each class of constituents (multiplicative prefixes being ignored), except that hydrogen is always cited last among electropositive constituents if actually classified as an electropositive constituent. 

Surface oxidation behavior is particularly important with regard to the use of glassy metals in as-quenched state. A general observation made with binary alloys is that the more electropositive constituent of the alloy tends to segregate to the surface upon oxidation. This procedure can occur already at lower temperature, and consequently the surface of freshly prepared alloys is likely to be covered with a thin layer of oxides of this constituent. This phenomenon has certainly contributed to controversy with regard to the catalytic properties of glassy metal surfaces, since in many of the earlier investigations little care was taken of this behavior and authors tacitly assumed that the surface composition resembles the bulk composition of the quenched materials. 

Termination for many electropositive constituents ttfbinary type namesT either inorganic or organic, either systematic of trivia] it... 

Where an element symbol occurs in the first column, the unmodified element name is listed in the second and diird columns. The unmodified name is generally used when the element appears as an electropositive constituent in the construction of a stoichiometric name (Sections IR-5.2 and IR-5.4). Names of homoatomic cations consisting of the element are also constructed using the element name, adding multiplicative prefixes and charge numbers as applicable (Sections IR-5.3.2.1 to IR-5.3.2.3). The sections mentioned refer to parts of Nomenclature of Inorganic Chemistry. lUPAC Recommendations 2005, see above. 

Binary compounds are named by citing the name of the electropositive constituent first, unmodified, followed by the name of the electronegative constituent, modified to end in -ide. For this purpose, an agreed series is used, based on the electrochemical series given above. 

Formula of radical Name as electropositive constituent of compounds Name as electronegative constituent of compounds... 

Multiple compounds are named by a straightforward extension of the system used for binary eompounds. The names of the electropositive constituents ate eited first, followed by the names of the eleetronegative ones. Names of constituents are often eited in electronegativity order (EO), but lUPAC reeommends alphabetical order (AO). The proportions of the eonstituents are indieated in the usual ways. 

Names of compounds are given in two (or more) parts, the (most) electropositive constituent (cation) first and the (most) electronegative (anion) last. Exceptions are made for intermetallic compounds (below), neutral co-ordination compounds (p. 15), addenda... 

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