Методическая разработка по английскому языку для студентов факультета химии и химической технологии " Simple Chemistry" Алматы 2017
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мет. разработка по химии
| Heterogeneous Mixtures
A heterogeneous mixture is not uniform. Different samples may have different compositions, like the example of chocolate chip ice cream. Concrete, soil, blood, and salad are all examples of heterogeneous mixtures. Suspensions When sand gets kicked up in a pond, it clouds the water. Soon the sand settles down, and is no longer mixed into the water. This is an example of a suspension. Suspensions are heterogeneous mixtures that will eventually settle. They are usually, but not necessarily, composed of phases in different states of matter. Italian salad dressing has three phases: the water, the oil, and the small pieces of seasoning. The seasonings are solids that will sink to the bottom, and the oil and water are liquids that will separate. Vocabulary notes Sand - песок to kick up – поднять (пыль) cloud - облако to settle down – оседать (на дно) is no longer - больше не to mix - смешать heterogeneous mixture – неоднородная смесь eventually – в конечном счете to settle - установить necessarily - обязательно to compose - составлять different - разный dressing – заправка, приправа state of matter – состояние вещества oil -масло piece of seasoning – немного приправы solid -твердый to sink - тонуть bottom - дно liquid - жидкий to separate – отделять a mixture смесь heterogeneous гомогенный a suspension взвесь, суспензия CobaltCobalt is a metallic element of the iron group. It resembles iron in appearance, but has a slight reddish tinge. Cobalt is harder than iron, but melts at a lower temperature and this element is somewhat heavier. Acids dissolve cobalt. Cobalt is very resistant to corrosion and wear, even at high temperatures. Cobalt is alloyed with chromium and tungsten, and it is used in the making of high-speed cutting tools. Cobalt has magnetic properties that make it suitable for alloys which are used to make strong permanent magnets. An important example is alnico, an alloy which contains aluminum, nickel, iron and cobalt. Cobalt is required in tiny amounts for proper nutrition. This element forms an essential part of Vitamin B 12. Cobalt 60, a radioactive isotope, is used as a commercial source of high - energy radiation. Cobalt was discovered by Georg Brandt, a Swedish chemist, in about 1735. Cobalt is not found in a pure state in nature, but it often occurs with nickel, copper or iron. Most cobalt is obtained as a by-product in the smelting of nickel or copper ores. Russia, Australia, Zambia, and Canada are the leading producers of cobalt. A variety of metallurgical processes are used to recover the cobalt, depending on the type of ore. Various compounds of cobalt are used as pigments in pottery, glass, enamels and paints. One of the best known is cobalt blue, a bluish-green compound of aluminum and cobalt oxide that has been long used in pottery. Some cobalt compounds are used as driers, substances that promote drying in paints, varnishes and printing inks. The symbol of cobalt is Co. The atomic number of cobalt is 27. Its atomic weight is 58.9332. Its melting point is 2,723 F. (1,495 C.). Cobalt has boiling point of 5,198 F. (2,870 C.). Its specific gravity is of 8.9. It belongs to Group VIII of the Periodic Table and has a valence of +2 or +3. Vocabulary notes cobalt кобальт to resemble быть похожим a slight reddish tinge легкий рыжеватый оттенок to be resistant to corrosion and wear устойчивый к коррозии и износу to be alloyed with легировать chromium хром tungsten вольфрам making изготовление high-speed cutting tools высоко скоростные режущие инструменты to be suitable for быть пригодным для permanent magnets постоянные магниты strong сильный, мощный, прочный alnico альнико nickel никель to be required for требоваться для a proper nutrition правильное питание essential важный commercial source промышленный источник high - energy radiation излучение высокой энергии a pure state в чистой форме copper медь to occur встречаться, происходить a by-product побочный продукт smelting плавка a variety of разнообразный depending on в зависимости a pigment пигмент various разнообразный pottery фаянсовая посуда enamels эмаль paints краски cobalt blue кобальтовая синева a drier сушильный агент to promote способствовать drying высыхание a varnish лак printing ink типографические чернила жүктеу/скачать 422,31 Kb. Достарыңызбен бөлісу:
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