Compounds ionic bonds

The organometallic compound chemistry of the 2A metals is similar to that of the 1A metals, and ionically bonded compounds predominate. As is the case with lithium in group 1 A, the first 2A element, beryllium, behaves atypically, with a greater covalent character in its metal-carbon bonds. 

I Because formulas are used to represent unbonded atoms, covalently bonded molecules (Section 5.5), and ionically bonded compounds (Section 5.2), a formula unit can represent an atom, a molecule, or the simplest unit of an ionic compound (Figure 5.8). For example. He represents an uncombined atom F2 represents a molecule of an element CO2 represents a molecule of a compound ... 

D. Dipole-dipole interactions only occur with ionically bonded compounds. 

Covalently bonded compounds have strong internal bonds but weak attractive forces between molecules. Because of these weak attractive forces, the melting and boiling points of these compounds are much lower than compounds with ionic bonds. Therefore, such compounds are much more likely to be liquids or gases at room temperature than ionically bonded compounds. 

Dissolution of an ionically bonded compound, sodium chloride, by water molecules. 

Ionic bonding is strong, and ionic-bonded compounds tend to be hard solids and have high melting points. Ionic bonding is also undirected—exerted uniformly in all... 

You have already learned that the strong electrostatic attraction between the positive and negative ions is known as the ionic bond. Compounds that are held together by ionic bonds are known as ionic compoimds. Because chemical compounds are overall electrically neutral, sodium chloride must be composed of one sodium ion for every chloride ion. To show this composition, the formula of the compound is written as NaCI. (Note that the ionic charges are not indicated in the formula.) In ionic compounds the simplest ratio of oppositely charged ions that gives an electrically neutral unit is represented in the formula and is called a formula unit. The formula unit for sodium chloride is NaCI, or one sodium ion and one chloride ion. 

Atoms combine with one another to give compounds having properties different from the atoms they contain The attractive force between atoms m a compound is a chemical bond One type of chemical bond called an ionic bond, is the force of attraction between oppositely charged species (ions) (Figure 1 4) Ions that are positively charged are referred to as cations, those that are negatively charged are anions... 

Whether an element is the source of the cation or anion in an ionic bond depends on several factors for which the periodic table can serve as a guide In forming ionic compounds elements at the left of the periodic table typically lose electrons giving a cation that has the same electron configuration as the nearest noble gas Loss of an elec tron from sodium for example yields Na which has the same electron configuration as neon... 

All the following compounds are charactenzed by ionic bonding between a group I metal cation and a tetrahedral anion Wnte an appropriate Lewis structure for each anion remembenng to specify formal charges where they exist... 

The above data are correct to about 20 kJ mole but it will be seen that the general trend among these more covalent bonds does appear to be a decrease in stability from carbon to silicon, i.e. the same way as was found for more ionic bonds in the halides. Thermodynamic data for metallorganic methyl compounds used in the produchon of semiconductor systems are shown in Table 2.3. 

The compounds which most nearly fit the clas-sicial conception of ionic bonding are the alkali metal halides. However, even here, one must ask to what extent it is reasonable to maintain that positively charged cations M+ with favourably... 

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