Nonmetal main-group elements

Are the nonmetals main group elements, transition elements, or inner transition elements ... 

In contrast to the nonmetals of the main group, elements the transition metals form only a relatively few compounds that are composed of simple isolated molecules, although they form many complex ions that exist as crystalline solids with an appropriate counter anion. 

B Main group elements are in the A families, while transition elements are in the B families. Metals, nonmetals, metalloids, and noble gases are color coded in the periodic table inside the front cover. 

The periodic table is a great help in deciding whether a binary oxide is likely to form an acidic or basic solution in water. For main-group elements, it is usually sufficient to note whether the parent element of the compound is a metal or a nonmetal. Most soluble metal oxides are strong bases in water. Conversely, many nonmetal oxides react with water to give acids ... 

Most metallic main-group elements form basic oxides and most nonmetallic elements form acidic oxides. Elements close to the diagonal frontier between metals and nonmetals form amphoteric oxides, as do some of the d-block elements. 

Now we can work out the formula of an ionic compound formed between the monatomic ions of two main-group elements, one a metal and the other a nonmetal. Unless a lower oxidation number is specified (as for the p-block metals), the metal atom loses all its valence electrons, and the nonmetal atom gains enough electrons to complete its valence shell. Then we adjust the numbers of cations and anions so that the resulting compound is electrically neutral. A simple example is calcium chloride. The calcium atoms ([Ar]4s2) each lose two electrons, to form... 

The oxides of main-group elements show periodic trends in properties. Oxides of metals tend to be ionic and to form basic solutions in water. Oxides of nonmetals are molecular and the anhydrides of acids. 

The periodic table is a classification scheme for elements that is tremendously useful in learning the properties of the elements. It consists of seven periods and 16 classical groups, or families (18 in a more modem but less useful version). Several of the groups have names, which beginning students need to leam. The elements are separated into metals and nonmetals on the periodic table. They are also subdivided into main group elements, transition elements, and inner transition elements. (Section 1.5)... 

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