Cations common monatomic

Some common monatomic cations and anions and their names are given in Table 2.3. 

In addition to the common monatomic halide ions, numerous polyatomic species, both cationic and anionic, have been prepared. Many readers will be familiar with the brown triiodide ion, l3, formed from I2 and I ... 

Many ionic componnds are binary compounds, or compounds formed from just two elements. For binary componnds the first element named is the metal cation, followed by the nonmetallic anion. Thus NaCl is sodium chloride. The anion is named by taking the first part of the element name (chlorine) and adding -ide. Potassium bromide (KBr), zinc iodide (Znl2), and aluminum oxide (AI2O3) are also binary componnds. Table 2.2 shows the -ide nomenclature of some common monatomic anions according to their positions in the periodic table. 

Some common monatomic cations and anions and their names are given in Table 2.3. The rules for naming binary ionic compounds are illustrated by the following examples ... 

Table 3.4 also contains the polarizability volumes of some common monatomic ions. It is seen that removal of the most loosely held electron in an alkali metal atom leads to a dramatic reduction of the polarizability. Similarly, addition of an electron to a halogen atom to form an anion leads to an increase of the polarizability. Comparing cations and anion, we see that halogen anions have considerably higher polarizabilities than alkali metal cations. 

Efgure 2>16 Some common monatomic ions of the elements. Main-groip elements usualy form a single monatomic ion. Note that members of a group have ions with the same charge. (Hydrogen is shown as both the cation in Group 1 A(1) and the... 

All common monatomic anions have noble gas configurations. Most monatomic cations of the representative elements (A groups) have noble gas configurations. The d- and /-transition elements form many compounds that are essentially ionic in character. Most d- and/-transition metal cations do not have noble gas configurations. 

The names and symbols of the common monatomic cations and anions are organized according to their charges in Figure 1.1. The names of many of the ions in the table include Roman numerals. These numerals are part of the Stock system of naming chemical ions and elements. You will read more about the Stock system and other systems of naming chemicals later in this chapter. 

The compounds described in Example 10-2 are binaty ionic compounds consisting of monatomic cations and monatomic anions. Commonly encountered ternary ionic compounds consist of monatomic and polyatomic ions. Bonding between atoms within the polyatomic ions is covalent. Some ternary ionic compounds are considered later in the chapter. 

A number of general features in Table 1-3 is apparent. Complexes may be cationic, neutral or anionic. Ligands may be simple monatomic ions, or larger molecules or ions. Many ligands are found as related neutral and anionic species (for example, water, hydroxide and oxide). Complexes may contain all of the same type of ligand, in which case they are termed homoleptic, or they may contain a variety of ligand types, whereby they are described as heteroleptic. Some ligands such as nitrite or thiocyanate can coordinate to a metal ion in more than one way. This is described as ambidentate behaviour. In such cases, we commonly indicate... 

Whereas many metals form monatomic cations, only six nonmetallic elements commonly form anions. 

It is commonly assumed that (he independent cations end anions will behave as ideal monatomic gases with heat capacities (at constant volume) of R. m Born, M. Verhtirdl. Dent. Physlk. Ces. 1919. 21, 13 Haber, F. Ibid. 1919, 21. 750. 

Ionic compounds are named with the cation (positive ion) first. Nearly all cations in inorganic chemistry are monatomic, meaning they just consist of one atom (like Ca2+, the calcium ion.) This atom will be a metal ion. For common ionic compounds, the alkali metals always have a 1+ charge and the alkali earth metals always have a 2+ charge. 

Some compounds contain polyatomic ions that behave much like monatomic anions. Compounds that contain these ions are called pseudobinary ionic compounds. The prefix pseudo- means false these compounds are named as though they were binary compounds. The common examples of such polyatomic anions are the hydroxide ion, OH , and the cyanide ion, CN. The ammonium ion, NH4+, is the common cation that behaves like a simple metal cation. 

It is commonly assumed that the independent cations and anions will behave as ideal monatomic gases with heal capacities (ai constant volume) of (K. 

Figure 8.22 shows the radii of some common main-group monatomic ions relative to their parent atoms. As you can see, ionic size increases down a group because the number of energy levels increases. Across a period, however, the pattern is more complex. Size decreases among the cations, then increases tremendously with the first of the anions, and finally decreases again among the anions. 

Table I contains values of x and rj for a number of atoms and common molecules. These are calculated from experimental values of I and A, many of which are now available. Most common molecules have negative electron affinities, meaning that kinetic energy must be supplied to an electron before the molecule will accept it. The table only gives a sampling of more extensive lists that have been compiled for molecules, atoms, free radicals and monatomic cations.

The names and formulas of some common cations are shown in TABLE 2.4 and on the back inside cover of the text. The ions on the left side in Table 2.4 are the monatomic ions that do not have more than one possible charge. Those on the right side are either polyatomic cations or cations with more than one possible charge. The Hg2 ion is unusual because, even though it is a metal ion, it is not monatomic. It is called the mercury(I) ion because it can be thought of as two Hg+ ions bound together. The cations that you will encounter most frequently are shown in boldface. You should learn these cations first. 

Most transition elements form more than one monatomic cation, each with a different charge. Most of these elements have one ion with a charge of +2. Example Iron has common cations Fe " and Fe. Copper has common cations Cu and Cu. ... 

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