M e t a l s a n d N o n m e t a l s
1. There are some distinctions between metals and nonmetals. Metals are distinguished from nonmetals by their high conductivity for hear and electricity, by metallic luster and by their resistance to electric current. Their use in industry is explained not only by those properties, but also by the fact that their properties, such as strength and hardness, can be greatly improved by alloying them with other metals. 2. There are several important group of metals and alloys. The common metals such as iron, copper, zinc, etc. Are produced in great quantities. 3. The so-called precious metals include silver, gold, platinum, and palladium. The light metals are aluminium, berillium and titanium. They are important in aircraft and rocket construction. 4. Many elements are classified as semimetals (bismuth, for example) because they have much poorer conductivity than common metals. 5. Nonmetals (carbon, silicon, sulphur) in the solid state are usually brittle materials without metallic luster and are usually poor conductors of electricity. Nonmetals show greater variety of chemical properties than common metals do. 6. Metals undergo corrosion, changing in this case their chemical and electromechanical properties. In order to protect metals from corrosion the products made of metals and steel are coated by some films (coatings). Organic coatings protect metals and steel from corrosion by forming a corrosion-resistant barrier between metal or steel and the corrosive environment. Прочтите текст и выполните следующие за ним упражнения. 2. Найдите в правой колонке русские эквиваленты английских слов и словосочетаний: 1. luster a. окружающая среда 2. property b. защищать от 2. quantity c. подвергаться 3. conductivity d. плохой проводник 4. solid state e. количество 5. brittle f. блеск 6. undergo g.сплав 7. to protect from h.свойство 8. environment i. проводимость 9. alloy j. твердое состояние 10. poor conductor k. хрупкий 11. distinction l. прочность 12. strength m. жесткость 13. hardness n. различие 3. Переведите на русский язык встречающиеся в тексте интернациональные слова: Metal, metallic, electricity, electric, fact, group, rocket, construction, element, material, corrosion, chemical, electromechanical, product, steel, organic, barrier, industry. Переведите на русский язык в письменной форме абзацы 1, 2 и 5. 5. Найдите соответствующие ответы на вопросы и напишите их в той последовательности, в которой заданы вопросы: Вопросы 1. By what properties are metals distinguished from nonmetals? 2. What common metals are produced in great quantities? 3. What metals are called light? 4. What properties do nonmetals have? 5. What is done to protect metals from corrosion? Ответы a. Iron, copper and zinc. b. They are usually poor conductors of heat and electricity. c. They are coated by some organic coatings. d. High conductivity for heat and electricity. e. Aluminium, berillium and titanium Закончите предложение, выбрав соответствующий вариант.
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