Nonmetals electron configuration

Phosphoms shows a range of oxidation states from —3 to +5 by virtue of its electronic configuration. Elemental P is oxidized easily by nonmetals such as oxygen, sulfur, and halides to form compounds such as 2 5 2 5 reduced upon reaction with metals to generate phosphides. The... 

As pointed out in Chapter 2, elements close to a noble gas in the periodic table form ions that have the same number of electrons as the noble-gas atom. This means that these ions have noble-gas electron configurations. Thus the three elements preceding neon (N, O, and F) and the three elements following neon (Na, Mg, and Al) all form ions with the neon configuration, is22s22p6. The three nonmetal atoms achieve this structure by gaining electrons to form anions ... 

This idea is readily extended to simple molecules of compounds formed by nonmetal atoms. An example is the HF molecule. You will recall that a fluorine atom has the electron configuration ls22s22p5. ft has seven electrons in its outermost principal energy level (n = 2). These are referred to as valence electrons, in contrast to the core electrons filling the principal level, n = 1. If the valence electrons are shown as dots around the symbol of the element, the fluorine atom can be represented as... 

FIGURE 2.3 When nonmetal atoms acquire electrons and form anions, they do so until they have reached the electron configuration of the next noble gas. 

To predict the electron configuration of a monatomic cation, remove outermost electrons in the order np, ns, and (n — l)d fora monatomic anion, add electrons until the next noble-gas configuration has been reached. The transfer of electrons results in the formation of an octet (or duplet) of electrons in the valence shell on each of the atoms metals achieve an octet (or duplet) by electron loss and nonmetals achieve it by electron gain. 

Valence and oxidation state are directly related to the valence-shell electron configuration of a group. Binary hydrides are classified as saline, metallic, or molecular. Oxides of metals tend to be ionic and to form basic solutions in water. Oxides of nonmetals are molecular and many are the anhydrides of acids. 

Ion formation is only one pattern of chemical behavior. Many other chemical trends can be traced ultimately to valence electron configurations, but we need the description of chemical bonding that appears in Chapters 9 and 10 to explain such periodic properties. Nevertheless, we can relate important patterns in chemical behavior to the ability of some elements to form ions. One example is the subdivision of the periodic table into metals, nonmetals, and metalloids, first introduced in Chapter 1. 

The compound is ionic — a metal (Al) bonded to a nonmetal (Cl). All ionic compounds are solids at room temperature and pressure. Aluminum has 13 electrons. As an ion, it will lose 3 electrons to become isoelectronic with neon. Thus the aluminum ion will have the electronic configuration ls22s22p6. 

The alkali metals, as we have seen, are frisky little devils. If there is any doubt about this, watch potassium (K) burst into flame in the presence of air, or watch sodium (Na) react violently in water. As we learned in Chapter 4, there are some electron configurations that are very stable, mainly those having eight outermost electrons. The alkali metals have one outermost electron, which they are anxious to dispose of. These electrons are usually transferred to nonmetals, such as oxygen (O), chlorine (Cl), fluorine (F), and bromine (Br), with a release of energy that is predictable, pronounced, and unforgettable. 

Much of chemistry consists of atoms bonding to achieve stable valence electron configurations. Nonmetals gain electrons or share electrons to achieve these configurations and metals lose electrons to achieve them. 

Examine each of the following electron configurations and then decide how many electrons must be lost or gained to reach a stable electron configuration. Is the element in question a metal or a nonmetal ... 

---