Periodic table nonmetals

Antimony [7440-36-0J, Sb, belongs to Group 15 (VA) of the periodic table which also includes the elements arsenic and bismuth. It is in the second long period of the table between tin and tellurium. Antimony, which may exhibit a valence of +5, +3, 0, or —3 (see Antimony compounds), is classified as a nonmetal or metalloid, although it has metallic characteristics in the trivalent state. There are two stable antimony isotopes that ate both abundant and have masses of 121 (57.25%) and 123 (42.75%). 

Arsenic [7440-38-2J, although often referred to as a metal, is classified chemically as a nonmetal or metalloid and belongs to Group 15 (VA) of the periodic table (as does antimony). The principal valences of arsenic are +3, +5, and —3. Only one stable isotope of arsenic having mass 75 (100% natural abundance) has been observed. 

Boron [7440-42-8] B, is unique in that it is the only nonmetal in Group 13 (IIIA) of the Periodic Table. Boron, at wt 10.81, at no. 5, has more similarity to carbon and siUcon than to the other elements in Group 13. There are two stable boron isotopes, B and B, which are naturally present at 19.10—20.31% and 79.69—80.90%, respectively. The range of the isotopic abundancies reflects a variabiUty in naturally occurring deposits such as high B ore from Turkey and low °B ore from California. Other boron isotopes, B, B, and B, have half-Hves of less than a second. The B isotope has a very high cross-section for absorption of thermal neutrons, 3.835 x 10 (3835 bams). This neutron absorption produces alpha particles. 

Periodic table. The group numbers stand above the columns. The numbers at the left of the rows are the period numbers. The black line separates the metals from the nonmetals. [Note A complete periodic table is given inside the front cover.)... 

The diagonal line or stairway that starts to the left of boron in the periodic table (Figure 2.7, page 31) separates metals from nonmetals. The more than 80 elements to the left and below that line, shown in blue in the table, have the properties of metals in particular, they have high electrical conductivities. Elements above and to the right of the stairway are nonmetals (yellow) about 18 elements fit in that category. 

Along the stairway (zig-zag line) in the periodic table are several elements that are difficult to classify exclusively as metals or nonmetals. They have properties between those of elements in the two classes. In particular, their electrical conductivities are intermediate between those of metals and nonmetals. The six elements... 

As pointed out in Chapter 2, elements close to a noble gas in the periodic table form ions that have the same number of electrons as the noble-gas atom. This means that these ions have noble-gas electron configurations. Thus the three elements preceding neon (N, O, and F) and the three elements following neon (Na, Mg, and Al) all form ions with the neon configuration, is22s22p6. The three nonmetal atoms achieve this structure by gaining electrons to form anions ... 

Arsenic and selenium, which fall directly below phosphorus and sulfur in the periodic table, are of interest for a variety of reasons. Arsenic is a true metalloid. A metallic form, called gray arsenic, has an electrical conductivity approaching that of lead. Another allotrope, yellow arsenic, is distinctly nonmetallic it has the molecular formula As4, analogous to white phosphorus, P4. Selenium is properly classified as a nonmetal, although one of its allotropes has a somewhat metallic appearance and is a semiconductor. Another form of selenium has the molecular formula Se8. analogous to sulfur. 

The metals are found toward the left side of the periodic table and the nonmetals are at the right side. A compound containing elements from the opposite sides of the periodic table can be expected to form a conducting solution when dissolved in water. Notice from our examples that hydrogen reacts with nonmetals to form compounds that give conducting solutions in water. In this sense, hydrogen acts like a metallic element. 

The elements that form network solids lie on the right side of the periodic table, bordering the elements that form molecular crystals on one side and those that form metals on the other. Thus they are intermediate between the metals and the nonmetals. In this borderline region classifications are sometimes difficult. Whereas one property may suggest one classification, another property may lead to a different conclusion. Figure 17-3 shows some elements that form solids that are neither wholly metallic nor wholly molecular crystals. 

The location of the metals in the periodic table is shown in Figure 17-4. We see that the metals are located on the left side of the table, while the nonmetals are exclusively in the upper right corner. Furthermore, the elements on the left side of the table have relatively low ionization energies. We shall see that the low ionization energies of the metallic elements aid in explaining many of the features of metallic behavior. 

B.15 Name each of the following elements (a) Sc (b) Sr (c) S (d) Sb. List their group numbers in the periodic table. Identify each as a metal, a nonmetal, or a metalloid. 

FIGURE C.7 The typical monatomic anions formed by a selection of elements in the periodic table. Notice how the charge on each ion depends on its group number. Only the nonmetals form monatomic anions under common conditions. 

The elements at the upper right of the periodic table have high ionization energies so they do not readily lose electrons and are therefore not metals. Note that our knowledge of electronic structure has helped us to understand a major feature of the periodic table—in this case, why the metals are found toward the lower left and the nonmetals are found toward the upper right. 

Now we move into the p block of the periodic table and encounter the complex bur fascinating world of the nonmetals. Here, close to the center of the periodic table, we meet strange properties, because the elements are neither so electropositive that they easily lose electrons nor so electronegative that they easily gain them. 

The elements show increasing metallic character down the group (Table 14.6). Carbon has definite nonmetallic properties it forms covalent compounds with nonmetals and ionic compounds with metals. The oxides of carbon and silicon are acidic. Germanium is a typical metalloid in that it exhibits metallic or nonmetallic properties according to the other element present in the compound. Tin and, even more so, lead have definite metallic properties. However, even though tin is classified as a metal, it is not far from the metalloids in the periodic table, and it does have some amphoteric properties. For example, tin reacts with both hot concentrated hydrochloric acid and hot alkali ... 

Why Do We Need to Know This Material The elements in the last four groups of the periodic table illustrate the rich variety of the properties of the nonmetals and many of the principles of chemistry. These elements include some that are vital to life, such as the nitrogen of proteins, the oxygen of the air, and the phosphorus of our bones, and so a familiarity with their properties helps us to understand living systems. Many of these elements are also central to the materials that provide the backbone of emerging technologies such as the nanosciences, superconductivity, and computer displays. 

The periodic table of the elements as used in common practice. The photos show ten pure elements, including six metals (Na, Mg, Cu, W, Au, Hg), one metalloid (Si), and three nonmetals (C, S, Cl). 

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. 

The six metalloids occupy a diagonal region of the periodic table between the metals and the nonmetals. 

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. 

Krebs, Robert E. The history and use of our earth s chemical elements a reference guide. Westport (CT) Greenwood P, 1998. ix, 346p. ISBN 0-313-30123-9 A short history of chemistry — Atomic structure The periodic table of the chemical elements — Alkali metals and alkali earth metals - Transition elements metals to nonmetals — Metallics and metalloids - Metalloids and nonmetals — Halogens and noble gases - Lanthanide series (rare-earth elements) — Actinide, transuranic, and transactinide series... 

A convenient way of displaying the elements is in the form of a periodic table, such as is shown on page 372 of this book. The basis for the arrangement of the elements in the periodic table will be discussed at length in Chap. 3. For the present, the periodic table will be regarded as a convenient source of general information about the elements. It will be used repeatedly throughout the book. One example of its use, shown in Fig. 1-1, is to classify the elements as metals or nonmetals. All the... 

---