METALS, NONMETALS, AND METALLOIDS

Atomic radii, ionization energies, and electron affinities are properties of individual atoms. With the exception of the noble gases, however, none of the elements exist in nature as individual atoms. To get a broader understanding of the properties of elements, we must also examine periodic trends in properties that involve large collections of atoms. 

The elements can be broadly grouped as metals, nonmetals, and metalloids ( FIGURE 7.12). (Section 2.5) Some of the distinguishing properties of metals and nonmetals are summarized in T TABLE 7.3. 

In the following sections, we explore some common patterns of reactivity across the periodic table. We will examine reactivity for nonmetals and metals in more depth in later chapters. 

Have a shiny luster various colors, although most are silvery 

Most metal oxides are ionic solids that are basic 

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The elements can be divided into categories metals, nonmetals, and metalloids. Examples of each appear in Figure U. Except for hydrogen, all the elements in the left and central regions of the periodic table are metals. Metals display several characteristic properties. For example, they are good conductors of heat and electricity and usually appear shiny. Metals are malleable, meaning that they can be hammered into thin sheets, and ductile, meaning that they can be drawn into wires. Except for mercury, which is a liquid, all metals are solids at room temperature. 

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. 

Describe the general characteristics of metals, nonmetals, and metalloids. 

Know the properties of metals, nonmetals, and metalloids and which elements on the periodic table belong to each group. 

Another way to look at the periodic table is to divide the elements into metals, nonmetals, and metalloids. Most of the elements in the table are metals. Metals are usually shiny and can be bent, hammered, or pulled into many different shapes without breaking into pieces. Metals are also good conductors, which means that heat and electricity can pass through them easily. Metals tend to give up electrons when they react with other elements. From this information, one could guess that most metals are found on the left side of the table, where the valence electron shells are mostly empty. 

The first step in being able to use the information contained in the periodic table is to understand how it is arranged. Most periodic tables are similar to one another but to lessen confusion the periodic table shown in Figure 1 will be used. One of the first things that stands out is that the table is composed of metals, nonmetals, and metalloids. 

You can use comparing and contrasting to help you classify objects or properties, differentiate between similar concepts, and speculate about new relationships. For example, as you read Chapters 1 and 2 you might begin to make a table in which you compare and contrast metals, nonmetals, and metalloids. As you continue to learn about these substances in the chapter on the Periodic Table, you can add to your table, giving you a better understanding of the similarities and differences among elements. 

Classifying the elements There are three main classifications for the elements—metals, nonmetals, and metalloids. Metals are elements that are generally shiny when smooth and clean, solid at room temperature, and good conductors of heat and electricity. Most metals also are malleable and ductile, meaning that they can be pounded into thin sheets and drawn into wires, respectively. Figure 6-6 shows several applications that make use of the physical properties of metals. 

Sketch a simplified version of the periodic table and indicate the location of groups, periods, metals, nonmetals, and metalloids. 

The Periodic Table Metals, Nonmetals, and Metalloids 4-2 Aqueous Solutions An Introduction... 

TEIE PERIODIC TABLE METALS, NONMETALS, AND METALLOIDS... 

Most properties of metals, nonmetals, and metalloids are determined by their valence electron configurations. The number of valence electrons that a metal has varies with its position in the periodic table. Valence electrons in metal atoms tend to be loosely held. Nonmetals have four or more tightly held electrons, and metalloids have three to seven valence electrons. 

The elements can be divided into three categories—metals, nonmetals, and metalloids. A metal is a good conductor of heat and electricity while a nonmetal is usually a poor conductor of heat and electricity. A metalloid has properties that are intermediate between those of metals and nonmetals. Figure 2.8 shows that the majority of known elements are metals only seventeen elements are nonmetals, and eight elements are metalloids. From left to right across any period, the physical and chemical properties of the elements change gradually from metallic to nonmetallic. 

Figure 9.1 A general comparison of metals and nonmetals. A, The positions of metals, nonmetals, and metalloids within the periodic table. B, The relative magnitudes of some key atomic properties vary from left to right within a period and correlate with whether an element is metallic or nonmetallic.

Ss was menrioncd in Section 2.2, the periodic table is a listing of all die known elements. There is so much more to this table, however. Most notably, the elements arc organized in the table based on their physical and chemical properties. One of the most apparent examples is how the elements are grouped as metals, nonmetals, and metalloids. 

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