Metals bonding with nonmetals

In general, metal atoms tend to lose electrons to form cations and nonmetal atoms tend to gain electrons to form anions. Thus, ionic compounds tend to be composed of metals bonded with nonmetals, as in NaCl. 

Recall from Chapter 5 that when metals bond with nonmetals, electrons are transferred from the metal to the nonmetal. The metal becomes a cation and the nonmetal becomes an anion. The attraction between the cation and the anion results in an ionic compoxmd. In Lewis theory, we represent this by moving electron dots from the metal to the nonmetal. For example, potassium and chlorine have the Lewis structures ... 

B Aluminum forms an amphoteric oxide in which it has the oxidation state +3 therefore, aluminum is the element. 14.3B Hydrogen is a nonmetal and a diatomic gas at room temperature. It has an intermediate electronegativity (x — 2.2), so it forms covalent bonds with nonmetals and forms anions in combination with metals. In contrast, Group 1 elements are solid metals that have low electronegativities and form cations in combination with nonmetals. 

The periodic table can give us many clues as to the type of reaction that is taking place. One general rule, covered in more detail in the Bonding chapter, is that nonmetals react with other nonmetals to form covalent compounds, and that metals react with nonmetals to... 

Metals react with nonmetals to form ionic bonds, and nonmetals react with other non-metals to form covalent bonds. 

After being physisorbed molecules may break open and their fragments can chemisorb. Chemisorption means strong reaction with the surface e.g., hydrogen or nitrogen gas with metallic surfaces (Figure 6.1). The atoms that were covalently bound to each other in molecules break off and form separate metallic bonds with the atoms of a metallic substrate surface such as platinum, nickel, or iron. There also can be a covalent bond between a surface atom and a nonmetal atom of an adsorbate or a er-bound organic moiety. Ionic bonds... 

I know just what you re thinking If metals react with nonmetals to form ionic bonds, and nonmetals react with other nonmetals to form covalent bonds, do metals react with other metals The answer is yes and no. 

In Chapter 8 we discussed that metals tend to have low ionization energies (their electrons are relatively easy to ronove) and that nonmetals tend to have negative electron affinities (they readily gain electrons). When a metal bonds with a nonmetal, it transfers one or more electrons to the nonmetal. The metal atom becomes a cation and the nonmetal atom an anion. These oppositely chaiged ions then attract one another, lowering their overall potential energy as described by Coulomb s law. The resulting bond is an ionic bond. 

Vanadium is a silvery whitish-gray metal that is somewhat heavier than aluminum, but lighter than iron. It is ductile and can be worked into various shapes. It is like other transition metals in the way that some electrons from the next-to-outermost shell can bond with other elements. Vanadium forms many complicated compounds as a result of variable valences. This attribute is responsible for the four oxidation states of its ions that enable it to combine with most nonmetals and to at times even act as a nonmetal. Vanadiums melting point is 1890°C, its boiling point is 3380°C, and its density is 6.11 glam . 

Carbon-12 is the basis for the average atomic mass units (amu) that is used to determine the atomic weights of the elements. Carbon is one of the few elements that can form covalent bonds with itself as well as with many metals and nonmetals. 

Their unique characteristics are a result of their outer shells having seven electrons, and thus requiring only one electron to become complete. This -1 oxidation state makes them extremely reactive with both metals and some nonmetal elements that form negative ions, and they may form either ionic or covalent bonds. They can also form compounds with each other these binary compounds of the halogens are called halides. ... 

As a nonmetal, chlorine exists as a greenish-yellow gas that is corrosive and toxic at room temperatures. As a halogen, chlorine is not found in the elemental (atomic) state but forms diatomic gas molecules (Cl j). As a very active negative ion with the oxidation state of —1, chlorine forms bonds with most metals found in groups I and II. 

Chlorine forms ionic bonds with almost all the metals and molecular bonds with the semimetals and nonmetals. With group 1 metals it produces well-known salts when chlorine s —1 ion combines with this group s +1 ions (e.g, NaCl, LiCl, and KCl). Group 2 metals have +2 ions and thus, when combined with —1 ions of chlorine, form salts such as magnesium chloride (MgCl ), calcium chloride (CaCy, and barium chloride (BaCy. 

VIA nonmetals) very easily gain new valence electrons. So metals and nonmetals tend to form bonds in which the metal atoms entirely surrender valence electrons to the nonmetals. Bonds with extremely unequal electron-sharing are called ionic bonds. 

The Alkali Metals.—Bonds of the alkali metals with all nonmetals are essentially ionic (with more than 50 percent ionic character—electronegativity difference greater than 1.7) except for Li—I, Li—C, and Li—S, with about 43 percent ionic character. 

As you become more familiar with transition metal dusters (no nonmetals in the framework) you will come to associate doso structures with numbers of electrons. A trimer will have 48 electrons, a tetrahedron will have 60 electrons, a trigonal bipyramid will have 72 electrons, and an octahedron will have 86. Some care is required, however, as can be illustrated with Os,H2(CO),0. An electron count gives us 46 electrons rather than 48. If, however, we allow for one Os—Os double bond, the electron count is as expected. In accord with this expectation, one osmium-osmium bond is found to be shorter than the other two and the complex shows the reactivity expected for an unsaturated complex. 

What factors determine whether an elemental substance adopts a metallic or a covalent structure From the simple model for metallic bonding, which views a metal as a lattice of cations embedded in a sea of delocalised electrons, it may be supposed that atoms having low ionisation potentials are most likely to become assembled as metallic substances. This correlation is far from perfect, however. Thus the first and second ionisation energies of mercury are comparable with those of sulphur, but the alchemists viewed elemental mercury and sulphur as the quintessential metal and nonmetal respectively. A closely-related correlation can be found with electronegativity. 

Metals form alloys with each other. They form ionic compounds with nonmetals. Nonmetals form only covalently bonded compounds with each other. As a result, metals become only positively (+) charged ions, whereas nonmetals become either negatively (-) or positively (+) charged ions. 

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