Page 342 - ABCTE Study Guide_Neat

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Chemical Bonds

Atoms react with one another in different ways, forming three basic types of chemical bonds:

Ionic bonds generally form between metal and nonmetal atoms, but always with both positive and
negative partners.

Covalent bonds generally form between nonmetal atoms.

Metallic bonds form between metal atoms.

When forming an ionic bond, the metal atom transfers its valence electrons to one or more nonmetal
atoms. An atom with an unbalanced number of positive and negative charges is called an ion. The metal
atom in this case becomes a positively charge ion called a cation and the nonmetal atom becomes a
negatively chargedanion. The cation and the anion both have more stable electron arrangements.
Because they have opposite charges, the ions are attracted to one another, forming a strong bond.

In nonmetal atoms, the valence electrons generally are not removed to form a cation, so a different type of
bonding occurs in nonmetals. In a covalent bond, two atoms share a pair of electrons. Usually, each atom
contributes one electron of the pair, although in some cases, one atom can contribute both electrons. This
type of chemical bonding is illustrated below.

Metal atoms bond together with metallic bonds. In these bonds, each metal atom loses all of its valence
electrons to form a cation with a positive charge of one or more. These electrons flow among the cations