Методическая разработка по английскому языку для студентов факультета химии и химической технологии " Simple Chemistry" Алматы 2017
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мет. разработка по химии
| Chlorine
Chlorine is a chemical element that is a greenish-yellow gas at ordinary temperature and pressure. The gas is poisonous and has a strong odour. It is about two and one-half times as heavy as air. Chlorine is not found free in nature. It is commonly found in combination with sodium. It forms sodium chloride (common salt). Chlorine is the most abundant member of the halogen family of chemical elements. Most chlorine is produced commercially by the passing of an electric current through a solution of water and sodium chloride. This process, which is called electrolysis, is carried out in a container which is called an electrolytic cell. The electric current decomposes the solution and produce chlorine and sodium hydroxide (caustic soda). Chlorine is used in many industrial processes and in the manufacture of many different products. It is widely used in the purification of drinking water and in the treatment of sewage. It is also used in the bleaching of paper and other products and in the separation of such metals as copper, lead, zinc, nickel, and gold from their ores. Important chlorine compounds include hydrochloric acid, sodium hypochlorite, and zinc chloride. Chlorine was first isolated by the Swedish chemist Karl Scheele in 1774. Sir Humphry Davy identified it as a distinct chemical element in 1810. The symbol of chlorine is Cl. Its atomic number is 17. Its atomic weight is 35.453. The melting point of chlorine is -149.8 F. (-101.0 C.). Its boiling point is -30.5 F. (-34.7 C.). Chlorine has specific gravity of : gas, 2.49 (air = 1); liquid, 1.56 (water = 1). Chlorine belongs to Group VIIA of the Periodic Table and can have a valence of -1, +1, 3, 5, or 7. There are two stable isotopes: Cl-35 and Cl-37. Vocabulary notes chlorine хлор poisonous ядовитый a strong odour сильный запах heavy тяжелый sodium chloride хлорид натрия common salt поваренная соль to be produced commercially получать на производстве passing пропускание an electric current электрический ток through через electrolysis электролиз an electrolytic cell электролитическая ячейка to decompose разлагать manufacture производство purification очистка treatment обработка sewage сточные воды bleaching отбеливание to use использовать copper медь lead свинец zinc цинк nickel никель gold золото ore руда hydrochloric acid соляная кислота sodium hypochlorite гипохлорит натрия zinc chloride хлорид цинка a liquid жидкость to isolate получать в чистом виде to identify выделить to belong to принадлежать atomic number атомный номер specific gravity удельный вес atomic weight атомный вес boiling point (b.p.) температура кипения melting point (m.p.) температура плавления to belong to принадлежать Lithium Lithium is a silver-white metallic chemical element. Lithium is the lightest metal and the third lightest of all the elements. Lithium is softer than lead and it is ductile. It is a good conductor of electricity, and can combine with many other metals to form alloys. When we expose it to air lithium tarnishes rapidly. It is therefore stored under gasoline and kerosene, or in airtight containers. At high temperatures lithium is capable of absorbing gases. We use lithium to remove oxygen and other gases in the manufacture of stainless steel, copper and copper alloys. The addition of the small percentage of lithium increases the strength of aluminum alloys, lead and tin. Lithium-magnesium alloys have numerous industrial and structural uses. Lithium is irradiated with neutrons to produce tritium, a radioactive isotope of hydrogen which is widely used in medicine. Lithium bromide and lithium chloride readily absorb moisture and are used in air conditioners and dry cell batteries. The element was discovered in 1817 by the Swedish chemist Johan A. Arfvedson. It is widely distributed in the earth’s crust. Lithium compounds are obtained from the ores by various chemical processes. The metal is usually obtained by electrolysis of lithium chloride. Lithium carbonate is used in the treatment of maniac-depressive illnesses. The chief ores of lithium are spodumene and petalite, two minerals which are composed of lithium, aluminum, silicon and oxygen, and amblygonite, a mineral which is composed of lithium, aluminum, fluorine, phosphorus and oxygen. The symbol of lithium is Li. The atomic number of lithium is 3. Its atomic weight is 6.941. Lithium has melting point of 356 F. (180 C.). Lithium has boiling point of 2,457 F. (1,347 C.). The specific gravity of the element is 0.53. Lithium has two stable isotopes: Li-6 and Li-7. It belongs to Group I-A of the Periodic Table and has a valence of +1. Vocabulary notes lithium литий silver-white серебристо-белый light легкий ductile пластичный to combine with соединяться an alloy сплав to expose подвергать воздействию to tarnish тускнеть rapidly быстро to store хранить gasoline бензин airtight containers герметичные контейнеры to capable of способен to absorb поглощать under под to remove удалять oxygen кислород stainless steel нержавеющая сталь copper alloys медные сплавы addition добавление to increase увеличивать strength прочность tin олово aluminum alloys алюминиевые сплавы lithium-magnesium alloys литиево-магниевые сплавы to have numerous industrial and structural uses использоваться во многих промышленных сферах и строительстве to irradiate with облучать neutron нейтрон tritium тритий a radioactive isotope радиоактивный изотоп lithium bromide бромид лития lithium chloride хлорид лития readily легко moisture влага dry cell batteries сухие электрические батареи to discover обнаруживать to be widely distributed быть широко распространенным the earth’s crust земная кора lithium carbonate карбонат лития treatment лечение spodumene сподумен petalite петалит to be composed of состоять из silicon кремний fluorine фтор phosphorus фосфор amblygonite амблигонит жүктеу/скачать 422,31 Kb. 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