Chemical properties of metals and nonmetals

There are many chemical differences between metals and nonmetals. These will become apparent in the following chapters. 

Some elements have very similar properties and are grouped into families. These include  

The gases He, Ne, Ar, Kr, and Xe were called inert when they were thought to be completely inactive. Their name was changed to noble after the xenon fluorides were discovered in 1962. This was because metals having a low activity (but nevertheless some activity) like gold and platinum are sometimes called noble as they are used for noble purposes. The change was inept. Inert need not imply complete inactivity, and noble is hardly apt (commoners breathe in these gases no less than nobles do ). 

Other families will be discussed in a later chapter. 

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Compare the physical and chemical properties of metals and nonmetals. 

Some Chemical Properties of Metals and Nonmetals Metals Nomnetals... 

It is the chemical properties of metals and nonmetals that interest us most. Metals tend to lose electrons and form positive ions, while nonmetals tend to gain electrons and form negative ions. When a metal reacts with a nonmetal, electrons are often transferred from the metal to the nonmetal. 

We will examine some differences in the physical and chemical properties of metals and nonmetals. Finally, we discuss some periodic trends in the chemistry of the active metals (groups 1A and 2 A) and of several nonmetals (hydrogen and groups 6A to 8A). 

The general properties of metals and nonmetals are distinct. Physical and chemical properties that distinguish metals from nonmetals are summarized in Tables 4-3 and 4-4. Not all metals and nonmetals possess all these properties, but they share most of them to varying degrees. The physical properties of metals can be explained on the basis of metallic bonding in solids (Section 13-17). 

Recognize the differences in chemical and physical properties of metals and nonmetals, including the basicity of metal oxides and the acidity of nonmetal oxides. (Section 7.6)... 

Table 11.2 compares the properties of metals and nonmetals. Chemically, the distinction between metals and nonmetals—elements that lose electrons in chemical reactions and those that do not—is not sharp. It can be drawn roughly as a stair-step... 

The 92 chemical elements that occur naturally in the earth can be divided into two main groups metals and nonmetals. Although the distinction between the two is not always sharp and clear, it can be said that over 70 of the 92 elements are metals among the fewer than 22 remaining non-metals, six are known as metalloids, which have properties that fall between those of metals and nonmetals (see Appendix I). 

In Chapter 4 we learned that the known elements can generally be divided into two classes, metals and nonmetals. On the periodic table, the elements are arranged by increasing atomic number in rows and columns. As these rows and columns are generated, the elements with metallic properties fall on the left side of the table, and the elements without metallic properties fall on the right side of the table. In Activity 6.1, we will examine the physical and chemical properties of metals to understand why they are so often the material of choice in jewelry making. 

The identification of the chemical forms of an element has become an important and challenging research area in environmental and biomedical studies. Two complementary techniques are necessary for trace element speciation. One provides an efficient and reliable separation procedure, and the other provides adequate detection and quantitation [4]. In its various analytical manifestations, chromatography is a powerful tool for the separation of a vast variety of chemical species. Some popular chromatographic detectors, such flame ionization (FID) and thermal conductivity (TCD) detectors are bulk-property detectors, responding to changes produced by eluates in a characteristic mobile-phase physical property [5]. These detectors are effectively universal, but they provide little specific information about the nature of the separated chemical species. Atomic spectroscopy offers the possibility of selectively detecting a wide rang of metals and nonmetals. The use of detectors responsive only to selected elements in a multicomponent mixture drastically reduces the constraints placed on the separation step, as only those components in the mixture which contain the element of interest will be detected... 

Metalloids have some chemical and physical properties of metals and other properties of nonmetals. In the periodic table, the metalloids lie along the border between metals and nonmetals. Silicon (Si) is probably the most well-known metalloid. Some metalloids such as silicon, germanium (Ge), and arsenic (As) are semiconductors. A semiconductor is an element that does not conduct electricity as well as a metal, but does conduct slightly better than a nonmetal. The ability of a semiconductor to conduct an electrical current can be increased by adding a small amount of certain other elements. Silicon s semiconducting properties made the computer revolution possible. 

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. 

The most fundamental classification of the chemical elements is into metals and nonmetals. Metals typically have the following physical proper-fies a lustrous appearance, the ability to change shape without breaking (they can be pulled into a wire or pounded into a thin sheet), and excellent conductivity of heaf and elecfricity. Nonmetals fypically do nof have these physical properties, although there are some exceptions. (For example, solid iodine is lustrous the graphite form of carbon is an excellent conductor of elecfricity and the diamond form of carbon is an excellent conductor of heaf.) However, it is the chemical differences between metals and nonmetals that interest us the most ... 

The heavy black line in Fig. 20.1 separates the metals from the nonmetals, except for one case. Flydrogen, which appears on the metal side, is a nonmetal. Some elementsjust on either side of this line, such as silicon and germanium, exhibit both metallic and non-metallic properties. These elements are often called metalloids, or semimetals. The fundamental chemical difference between metals and nonmetals is that metals tend to lose their valence electrons to form cations, which usually have the valence electron configuration of the noble gas from the preceding period. On the other hand, nonmetals tend to gain electrons to form anions that exhibit the electron configuration of the noble gas in... 

The elements which directly precede the noble gases—fluorine, chlorine, bromine, and iodine, atomic numbers 9, 17, 35, and 53, respectively—as a group have similar properties. The members of this group are called the halogens. They have none of the properties of metals, and are therefore known as nonmetals. Other groups of similar chemical properties can be identified in the same way. 

We learn that the physical and chemical properties of metals are different from those of nonmetals. These properties arise from the fundamental characteristics of atoms, particularly ionization energy. Metalloids display properties that are intermediate between those of metals and those of nonmetals. 

The more an element exhibits the physical and chemical properties of metals, the greater its metallic character. As indicated in Figure 7.12, metallic character generally increases as we proceed down a group of the periodic table and decreases as we proceed right across a period. Let s now examine the close relationships that exist between electron configurations and the properties of metals, nonmetals, and metalloids. 

Some Physical and Chemical Properties of Metals, Nonmetals, and Metalloids... 

Group VIA, like the preceding groups, shows the trend from nonmetallic to metallic as you proceed from top to bottom of the column of elements. Oxygen and sulfur are strictiy nonmetallic. Although the chemical properties of selenium and tellurium are predominantly those of nonmetals, they do have semiconducting allotropes as expected of metalloids. Polonium is a radioactive metal. 

Notice that they are numbered from 1 to 18 from left to right. Each group contains elements with similar chemical properties. For example, the elements in Group 2 are beryllium, magnesium, calcium, strontium, barium, and radium. All of these elements are reactive metals with similar abilities to bond to other kinds of atoms. The two major categories of elements are metals and nonmetals. Metalloids have properties intermediate between those of metals and nonmetals. 

The range of oxidation states elements can assume is one of the chemical properties of elements. Since the chemical properties of metalloids tend to resemble the chemical properties of nonmetals more than they do the chemical properties of metals, metalloids (e.g. B, Si, and As) can often assume both positive and negative oxidation states. 

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