Metalloid location

What are the representative elements In what region(s) of the periodic table are these elements found In what general area of the periodic table are the metallic elements foimd In what general area of the table are the nonmetals found Where in the table are the metalloids located ... 

FIGURE B.12 The location ot the seven elements commonly regarded as metalloids these elements have characteristics of both metals and nonmetals. Other elements, notably beryllium and bismuth, are sometimes included in the classification. Boron (B), although not resembling a metal in appearance, is included because it resembles silicon (Si) chemically. 

In the anion electrochemical series, sulfur, being the less noble element compared to its heavier congeners, occupies an intermediate position between iodine and selenium [(+)F, Cl, Br, I, S, Se, Te(-)]. Selenium, regarded as a metalloid, is a relatively noble element. Tellurium is rather an amphoteric element it can enter into solution in the form of both cations and anions. Regarded as a metal, i.e., with respect to its cations, tellurium occupies a position between copper and mercury. Regarded as a metalloid, i.e., with respect to its anions, it is located on the extreme right of the above series. 

The prototype hard metals are the compounds of six of the transition metals Ti, Zr, and Hf, as well as V, Nb, and Ta. Their carbides all have the NaCl crystal structure, as do their nitrides except for Ta. The NaCi structure consists of close-packed planes of metal atoms stacked in the fee pattern with the metalloids (C, N) located in the octahedral holes. The borides have the A1B2 structure in which close-packed planes of metal atoms are stacked in the simple hexagonal pattern with all of the trigonal prismatic holes occupied by boron atoms. Thus the structures are based on the highest possible atomic packing densities consistent with the atomic sizes. 

You should highlight or color the metalloid elements on the periodic table for practice to help you locate the metals and nonmetals. Left = Metals Right = Nonmetals. 

Boron is a semimetal, sometimes classed as a metallic or metalloid or even as a nonmetal. It resembles carbon more closely than aluminum, the latter of which is located just below boron in group 13. Although it is extremely hard in its purified form—almost as hard as diamonds—it is more brittle than diamonds, thus limiting its usefulness. It is an excellent conductor of electricity at high temperatures, but acts as an insulator at lower temperatures. It is less reactive than the elements below it in group 13... 

Although tin is located in group 14 as a metalloid, it retains one of the main characteristics of metals in reacting with other elements, it gives up electrons, forming positive ions just as do all metals. 

Tellurium is a silver-white, brittle crystal with a metallic luster and has semiconductor characteristics. It is a metalloid that shares properties with both metals and nonmetals, and it has some properties similar to selenium and sulfur, located just above it in group 16 of the periodic table. 

In 2006, the speciation of metals and metalloids (As, Bi, Hg, Pb, Sb, Se and Sn) associated with alkyl groups and biomacromolecules in the environment was critically reviewed by Hirner.85 More than 60 species of alkylated metals and metalloids have been found in different ecosystems and terrestrial locations all over the world.85-87 These alkylated metals or metalloids are of interest due to their toxicological properties (e.g. monomethyl mercury, MMHg, which gained worldwide attention during the Minamata tragedy, and are not only known to be produced by microbial methylation within most anaerobic compartments of the environment, but also in the course of enzymatic transformation during human metabolism.85... 

Nonmetals An element located toward the upper right of the periodic table that is neither a metal nor a metalloid. 

FIGURE J.3 The location of acidic, amphoteric, and basic oxides in the main groups of the periodic table. Metals form basic oxides, nonmetals form acidic oxides. The diagonal band of amphoteric oxides closely matches the diagonal band of metalloids (recall Fig. B.18). 

Metals are located on the left side of the periodic table. Metals tend to form cations, are generally ductile and malleable, and are good electrical and thermal conductors. Nonmetals are located on the right side of the periodic table. Nonmetals tend to form anions and have a wide variety of physical properties. Metalloids look like metals but have electrical conductivity intermediate between metals and nonmetals. For this reason, metalloids are called semiconductors. 

The semimetals, or metalloids, are known to exhibit some of the properties of metals and some of those of nonmetals. The semimetals are B, Si, Ge, As, Sb, Te, and At. They are highlighted in bold in the partial periodic table in Figure 4.1. The elements located to the left of the semimetals are the metals those to the right of the semimetals are the nonmetals. Identifying an element as a metal, nonmetal, or semimetal is important in identifying periodic trends and in identifying the types of bonds that atoms will form with each other. 

Germanium is a metalloid. A metalloid is an element that has characteristics of both metals and non-metals. Germanium is located in the middle of the carbon family, which is Group 14 (IVA) in the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. Carbon and silicon are above germanium and tin and lead are below it. 

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

Thinking Criticaiiy A gaseous element is a poor conductor of heat and electricity, and is extremely nonreactive. Is the element likely to be a metal, nonmetal, or metalloid Where would the element be located on the periodic table Explain. 

All of the elements on the periodic table break up into three major categories metals, nonmetals, and semimetals. Metals are elements with relatively few valence electrons, which tend to form positive ions by losing one or more electrons. Metals tend to be good conductors of heat and electricity. Nonmetals are elements that have more valence electrons and tend to form negative ions by gaining one or more electrons. Nonmetals tend to be poor conductors of heat and electricity. Semimetals, which are also called metalloids or semiconductors, tend to have some characteristics of metals and some of nonmetals. Figure 3-7b shows a periodic table that shows the locations of the three basic types of elements. 

Table 10-1 contains lists of the common amphoteric hydroxides. Three are hydroxides of metalloids, As, Sb, and Si, which are located along the line that divides metals and nonmetals in the periodic table. 

The color coding in the periodic table on pages 92 and 93 identifies which elements are metals (blue), nonmetals (yellow), and metalloids (green). The majority of the elements are metals. They occupy the entire left side and center of the periodic table. Nonmetals occupy the upper-right-hand corner. Metalloids are located along the boimdary between metals and non-metals. Each of these classes has characteristic chemical and physical properties, so by knowing whether an element is a metal, nonmetal, or metalloid, you can make predictions about its behavior. Elements are classified as metals, metalloids, or nonmetals on the basis of their physical and chemical properties. 

Cluster boundary decoration by metalloid atoms may occur due to small-atom locations in noncoincident sites. It is similar to the decorating of the Fe-Ni-B alloy boundaries with boron atoms (Fig. 6.2). 

Figure 19. Transformations of Fe(II, III) at an oxic anoxic boundary in the water or sediment column (modified from Davidson, 1985). Peaks in the concentration of solid Fe(III) (hydr)oxides and of dissolved Fe II) are observed at locations of maximum Fe(III) and Fe(II) production, respectively. The combination of ligands and Fe(ll) produced in underlying anoxic regions are most efficient in dissolving Fe(III) (hydr)oxides. Redox reactions of iron—oxidation accompanied by precipitation, reduction accompanied by dissolution—constitute an important cycle at the oxic-anoxic boundary which is often coupled with transformations (adsorption and desorption) or reactive elements such as heavy metals, metalloids, and phosphates.

Draw a rough sketch of a periodic table (no details are required). Indicate regions where metals, non-metals, and metalloids are located. 

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