Element systematic nomenclature

Many elements can give rise to more than one elementary substance. These may be substances containing assemblages of the same mono- or poly-atomic unit but arranged differently in the solid state (as with tin), or they may be assemblages of different polyatomic units (as with carbon, which forms diamond, graphite and the fullerenes, and with sulfur and oxygen). These different forms of the element are referred to as allotropes. Their common nomenclature is essentially trivial, but attempts have been made to develop systematic nomenclatures, especially for crystalline materials. These attempts are not wholly satisfactory. 

Specialists in nomenclature recognise two different categories of nomenclature. Names that are arbitrary (including the names of the elements, such as sodium and hydrogen) as well as laboratory shorthand names (such as diphos and LithAl) are termed trivial names. This is not a pejorative or dismissive term. Trivial nomenclature contrasts with systematic nomenclature, which is an assembly of rules, themselves arbitrary. The function of specialists in nomenclature is to codify such rules so that everyone can use them to identify pure substances, rather like many of us use an alphabet to represent words. There may be more than one way to name a compound or species, and no one way may be superior to all the others. Names also vary in complexity, depending upon how much information needs to be conveyed. For example, a compositional name conveys less information than a structural (or constitutional) name, because this includes information about the arrangement of atoms in space. 

Chemists have developed names for materials since the beginning of the science. Initially, the names were always trivial, because the systematics of molecular structure were completely unknown. The names of the elements are still essentially trivial, but these are the basis of systematic nomenclature. 

The transuranium elements are the elements following uranium in the periodic table. The elements from rutherfordium (Rf, Z = 104) through meitnerium (Mt, Z = 109) were formally named in 1997. The transmeitnerium elements, the elements beyond meitnerium (including hypothetical nuclides that have not yet been made), are named systematically, at least until they have been identified and there is international agreement on a permanent name. The systematic nomenclature uses the terms in Table 17.2. For example, the element with Z = 111, one atom of which was first made in 1994, will be called unununium, Uuu, until it is finally named. 

Although the general term carbide applies to the binary compounds of the element carbon, this term is used in systematic nomenclature only when carbon is the more electronegative of the two elements involved. Thus, C02 is called carbon dioxide and not oxygen carbide since oxygen is more electronegative than carbon. Although carbon forms binary compounds with most of the nonmetals, metalloids, and metals, only a few of the more common members of this class are considered here. 

The compound has two chirality centres and three pseudo chirality centres. There is however, only one (achiral) diastereomer of the compound shown in the question. The two isomers can be distinguished from one another solely on the relative position of the chlorine or bromine atoms which lie in a plane which also happens to be the plane of symmetry of the molecule (this is the only symmetry element present, therefore the symmetry point group is Cs). It is possible in this instance to specify the configuration unequivocally using the descriptors E and Z. However, in systematic nomenclature the complete configuration of all the stereogenic centres is specified. Thus the (so-called) Z isomer is (ls,3r,5 ,6r,7S)-l,6-dibromo-3,6-dichloroadamantane and the isomer is (ls,3r,5 ,6s,7S)-l,6-dibromo-3,6-dichloroadamantane, i.e. the two isomers can be distinguished simply by the descriptor used for position 6. 

The symbols for particles, chemical elements and nuclides have been discussed in section 2.10. The recently recommended systematic nomenclature and symbolism for chemical elements of atomic number greater than 103 is briefly described in footnote U to table 6.2. 

Phosphorous is a five-valent element, and its natural oxide is P2O5, phosphorous pentoxide. It is a highly hygroscopic powder and readily reacts with water to form phosphoric acid (H3PO4). This acid when reacted with various aUcaline compounds forms phosphates. These and other modified compounds are linear or chain, cyclic or ring, and branch chain polymers. Because these compounds are polymeric, phosphates can provide a continuous structure and, hence, form good ceramics. The reader is referred to Topics in Phosphorus Chemistry by Westman [1] for details. Because of the variety of polymeric compounds formed by phosphorous, a systematic nomenclature is used in phosphate chemistry. 

The nomenclature reform of the French chemists was of fundamental importance, replacing the old body-spirit terminology with new terms, based on oxygen. The calx was now termed the oxide, and the spirit of vitriol became sulfuric acid. The assumption that oxygen was the acid generator, as its name implied, was flawed, but the systematic nomenclature based on the increase of acidity with increase of oxygen content lived on, e.g. the acidic component of the sulfides, sulfites, and sulfates. The definition of a chemical element as the latest term whereat chemical analysis has arrived ... 

IR-3.1.1 Systematic nomenclature and symbols for new elements IR-3.2 Indication of mass, charge and atomic number using indexes (subscripts and superscripts)... 

Newly discovered elements may be referred to in the scientific literature but until they have received permanent names and symbols from IUP AC, temporary designators are required. Such elements may be referred to by their atomic numbers, as in element 120 for example, but IUPAC has approved a systematic nomenclature and series of three-letter symbols (see Table II).2... 

The first step in the development of a supporting theory was the introduction, by Dalton in 1803, of symbols representing single atoms rather than any amount of an element. This led to the first attempts to represent chemical structures by structure diagrams (Figure 3). The structure diagrams provided the needed theoretical basis for the recently-proposed systematic nomenclature and laid the foundation for the continued development of systematic nomenclature and for the eventual introduction and devdopment of notations and connection tables. 

For the smallest chemical substances, elements, and the largest, principally biopolymers, systematic nomenclature reverts to simpler forms. In the case of atoms, the element names apply such as, lawrencium. i.sotope of mass 254 . Undiscovered elements receive some substitute name such as element number 234 or the more systematic lUPAC names concatenated from word fragments representing the numerals 0 through 9,... 

The aim of chemical nomenclature is to be simple but unambiguous. A systematic name specifies the elements present in the molecule and the numbers of atoms of each element. 

The basic materials of systematic chemical nomenclature are the element names and symbols, which are, of themselves, trivial, with the exception of the systematic, provisional names and symbols for the elements of atomic number greater than 109. These provisional names will be superseded eventually by trivial names and symbols. In any case, they make little impact on general chemical practice. 

Although symbols are not a part of nomenclature, the two are closely related, and the former have played an extremely important role in chemistry. Because of the difficulty of establishing priority of discovery for most of the elements of atomic number above 100, and because of the need to refer to hypothetical elements with higher atomic numbers, IUPAC has developed interim systematic symbols and names for such elements. 

Many compounds were given informal, common names before their compositions were known. Common names include water, salt, sugar, ammonia, and quartz. A systematic name, on the other hand, reveals which elements are present and, in some cases, how the atoms are arranged. The systematic naming of compounds, which is called chemical nomenclature, follows a set of rules, so that the name of each compound need not be memorized, only the rules. 

U) The names and symbols given here are systematic and based on the atomic numbers of the elements as recommended by the IUPAC Commission on the Nomenclature of Inorganic Chemistry [22]. The names are composed of the following roots representing digits of the atomic number ... 

Sometimes the minors with the appropriate signs prefixed are called the signed minors or cofactors of the elements ai, 2 3 tc. This nomenclature will not be used systematically, a minor being supposed to carry its appropriate sign. 

The systematic naming of an inorganic substance involves the construction of a name from entities which are manipulated in accordance with defined procedures to provide compositional and structural information. The element names (or roots derived from them or from their Latin equivalents) (Tables I and II, see also Chapter IR-3) are combined with affixes in order to construct systematic names by procedures which are called systems of nomenclature. 

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