The easy loss of this valence electron means that these metals readily form stable cations with a charge of 1+. This combination makes it very easy to remove the single electron in the outermost (valence) shell of each. The alkali metals have the largest atomic radii and the lowest first ionization energy in their periods. The properties of the alkali metals are similar to each other as expected for elements in the same family. The name alkali metal is in reference to the fact that these metals and their oxides react with water to form very basic (alkaline) solutions. Although hydrogen is in group 1 (and also in group 17), it is a nonmetal and deserves separate consideration later in this chapter. The alkali metals lithium, sodium, potassium, rubidium, cesium, and francium constitute group 1 of the periodic table. Although beryllium, cadmium, mercury, and lead are readily available, there are limitations in their use because of their toxicity. Elemental magnesium, aluminum, zinc, and tin are important in the fabrication of many familiar items, including wire, cookware, foil, and many household and personal objects. The coating is a nonreactive film of oxide or some other compound. The formation of this protective coating is passivation. Part of the reason why these elements react slowly is that these elements react with air to form a protective coating. However, it is possible to isolate elemental beryllium, magnesium, zinc, cadmium, mercury, aluminum, tin, and lead from their naturally occurring minerals and use them because they react very slowly with air. Most of the representative metals do not occur naturally in an uncombined state because they readily react with water and oxygen in the air. Nonmetals are shown in green, metalloids in purple, and the transition metals and inner transition metals in blue. A salt is an ionic compound consisting of cations and anions.įigure 18.2 The location of the representative metals is shown in the periodic table. In general, the combination of a metal and a nonmetal produces a salt. Unlike metals, which typically form cations and ionic compounds (containing ionic bonds), nonmetals tend to form anions or molecular compounds. The remaining representative elements are nonmetals. A metalloid is an element that has properties that are between those of metals and nonmetals these elements are typically semiconductors. In addition to the representative metals, some of the representative elements are metalloids. The radioactive elements copernicium, flerovium, polonium, and livermorium are also metals but are beyond the scope of this chapter. There are 20 nonradioactive representative metals in groups 1, 2, 3, 12, 13, 14, and 15 of the periodic table (the elements shaded in yellow in Figure 18.2). Metallic character results from an element’s ability to lose its outer valence electrons and results in high thermal and electrical conductivity, among other physical and chemical properties. Metals among the representative elements are the representative metals. The d orbitals fill with the elements in group 11 therefore, the elements in group 12 qualify as representative elements because the last electron enters an s orbital. The transition elements are elements where the d orbitals (groups 3–11 on the periodic table) are filling, and the inner transition metals are the elements where the f orbitals are filling. The representative elements are elements where the s and p orbitals are filling. It is possible to divide elements into groups according to their electron configurations. The primary focus of this section will be the application of periodicity to the representative metals. We begin this section by examining the behaviors of representative metals in relation to their positions in the periodic table. Make predictions about the periodicity properties of the representative elements.By the end of this section, you will be able to:
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