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Unformatted text preview: Chapter 21: Nonmetals, Metalloids, Metals, and Metal Complexes Multiple Choice Section 21.1 1. The metalloids are found in nature primarily a. in compounds where they are combined with metals. * b. in compounds where they are combined with nonmetals. c. in alloys where they are combined with metals. d. in alloys where they are combined with nonmetals. e. in the free state as the elements themselves. Section 21.1 2. When they are found in compounds in nature, metalloids are obtained in their elemental state from these compounds by a. roasting the compounds in air. * b. chemical reduction using carbon or hydrogen as the reducing agent. c. chemical oxidation using hydrogen as the oxidizing agent. d. chemical reduction using sodium or magnesium as the reducing agent. e. chemical reduction using hydrazine or carbon monoxide as the reducing agent. Section 21.1 3. An important use of silicon and germanium is a. as additives in the manufacture of special steels with specific characteristics. b. in fabrication of coatings used in the building industry. * c. in semiconductors used in fabrication of electronic devices. d. in radiation detectors. e. in high density electromagnets used for magnetic resonance work. Section 21.1 4. The most abundant element in the earth’s atmosphere is a. oxygen. * b. nitrogen. c. argon. d. helium. e. hydrogen. Section 21.1 5. Carbon, when found in the free state in nature, is usually in the form of * a. graphite b. diamond c. carbon monoxide d. γ-carbon e. 14 C 188 Section 21.1 6. The halogens Cl 2 , Br 2 , and I 2 can be conveniently prepared from their simple ionic compounds in the laboratory by a. reduction with magnesium. b. reducing using carbon as the reducing agent. c. oxidation using hydrogen as the oxidizing agent. * d. oxidation using MnO 2 as the oxidizing agent. e. oxidation using carbon as the oxidizing agent. Section 21.1 7. Chlorine is important commercially in the manufacture of a variety of chemicals. It is obtained primarily on a large scale by a. reduction of particular solutes in sea water or brine using magnesium as a reducing agent. b b. oxidation of particular solutes in sea water or brine using oxygen as an oxidizing agent. * c. electrolysis of sea water or brine. d. oxidation of particular solutes in sea water or brine using potassium permanganate as the oxidizing agent. e. oxidation of calcium chloride using sodium chloride as the oxidizing agent. Section 21.1 8. Phosphorus can be obtained from calcium phosphate (which is available from natural sources) by a. reduction with hydrogen. b. reduction with sodium metal. * c. reduction with a mixture of carbon (the reducing agent) and SiO 2 (sand). d. reduction with magnesium metal....
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- Spring '10
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