English for chemists

Lesson 8
ГРАММАТИКА: Составное глагольное сказуемое. Формы инфинитива и их значения. Модальные глаголы и их заместители.
Section I
Ex. 1. Pronounce the following words:

-gh
в середине и в конце слова не произносится

but: [f]
s М

M

^sh til

high, light, slight, night, might, weigh, weight, though, through, although, thorough, thoroughly, brought

tough, enough, laugh

sit, such, solution, mass, serve, student, list, substance, selenium, discover, sister, sulphur, less. same, several, iust. so. similar is, as, has, these, boys, ores, please, pens, observe
she, shall, shop, should, show, reddish, share, short

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b) nevertheless [.nevodo'les], giant [’d3aiont], tellurium [to'ljooriom], selenium (si'li:ni3m), variety [vo'raioti], curious ('kjuorios], conductivity [.kondAk'tiviti], colloid ['kobid], gelatin fdscbtin], hydrazine ['haidro,zi:n], hydrate ('haidrcit], suspension [sos'penjn]
Ex. 2. Read the following words and say what Russian words help to understand their meaning:
elementary, interesting, giant, valence, allotropic, characteristic, variety, electrical, condition, colloid, gram, gelatin, hydrazine, hydrate, minute, observe, protective, serve, suspension
Ex. 3. Pay attention to the following way of word-building:
red + -isli —>reddish (красн-ым + -оват(ый) ■=красноватый) greenish, bluish, yellowish, pinkish, brownish
основа слова + -/и/ -> прилагательное
useful, beautiful, helpful, careful, truthful, thankful, peaceful, successful основа слова + -sion Цп), fen] —»существительное
conversion, suspension, inversion; division, explosion, corrosion
Ex. 4. Arrange the following words in the alphabetic order and find their meaning in a dictionary:
textbooks, nevertheless, ores, infer, alike, pieces, coating, flame, peculiar, curious, varies, prolong
Ex. 5. Find the meaning of the words or expressions with the italicized words in a dictionary and translate the sentences into Russian.
1. Selenium is well worth studying. 2. It is worthwhile reading this textbook. 3. We compared the atomic weights of many elements.

4. 
   Selenium has an atomic weight of78.96 as compared with 32 for sulphur.
   
5. 
   His respect to his tcachcrs was great. 6. In this respect selenium differs from sulphur.
   

Text 8 A
Selenium

The element selenium usually receives scant* attention in elementary textbooks, probably because it is of little importance commercially. Nevertheless, it is an interesting substance and well worth studying.
Selenium was discovered by the Swedish giant among chemists, Berzelius.

The clement is not abundant, but it is to be found in various ores.

* scant — скудный

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Selenium is the sister element of sulphur, forming with tellurium the elements occurring in Group VI. It has an atomic weight of 78.96 as compared with 32 for sulphur. From the fact that the atomic weight is more, wc may infer that selenium should be less active than sulphur. Its valences arc: +2, +4, and +6, the same as those of sulphur. It can be found in several allotropic forms, just as sulphur docs. It will be helpful to remember that the two elements arc very much alike in their chcmical properties and so the reactions of sulphur arc similar to those of selenium.
A piccc of amorphous selenium is rather hard and quite brittle, just as sulphur is. The dark colour of the clement, the silver-grey coating on its surface arc characteristic. Another variety of the clement is red.
The element is both odourless and tasteless. It bums as readily as sulphur docs, with a reddish-blue flame and the peculiar odour. In working with selenium, beware* of the odour of its hydrogen compound; it is worse than that of hydrogen sulphide.
One curious property of selenium should be mentioned. The substancc varies in its electrical conductivity according to the amount of light that falls upon it. Wc should remember that sulphur is a nonconductor. An experiment shows that selenium differs in this rcspcct.
Under proper conditions selenium can form a colloid. One gram of selenium dioxide is dissolved in 500 ml of water. To 50 ml of this solution wc add, after heating, 10 ml of a onc-pcrccnt solution of gelatin, and then, drop by drop,* 60 ml of hydrazine hydrate (1:2,000 of water). Wc must remember to keep it just below the boiling point for 16 minutes. The beautiful peach-pink** colour of the colloid is to be observed. The colloid can be made without gelatin, but the protective colloid serves to prolong the life of the colloidal suspension.
Words and Word-Combinations to Be Memorized
according to, alike, be alike, allotropic, amoiphous, another, coating, colloid, compare, as compared, condition, conductivity, conductor, differ, drop, clcctrical, elementary, fall, few, a few, gram, heat, hydrate, importance, keep, mention, nevertheless, ore, piccc, proper, quite, rather, readily, in this respect, selenium, several, silver, sulphur, sulphide, surface, suspension, tellurium, textbook, variety, vary, be worth (while).
Ex. 6. Give the Russian equivalents for the following:
elementary textbooks, receive attention, be of importance, probably, nevertheless, bccausc, be worth studying, among, in various ores, the sister clement, as compared with, be less activc, be more activc, several allotropic forms, just as, remember, be very much alike, be similar to, amorphous

• 
  bew are — остерегаться
  

• 
  peach-pink — псрсиково-ргоовый (чист)
  

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selenium, piece, rather hard, dark colour, the silver-grey coating, on the surface, another variety of, both... and..., bum readily, be worse than, mention, electrical conductivity, according to, fall upon smth., remember, be a conductor, be a nonconductor, differ in some rcspcct, under proper conditions, heating, a one-percent solution, drop by drop, the protective colloid, prolong the life
Ex. 7. Give the English equivalents for the following:
вероятно, иметь большое промышленное значение, тем не менее, интересный, среди химиков, в различных рудах, атомный вес, по срав­ нению с, быть более (менее) активным, такая же валентность, не­ сколько аллотропных форм, быть полезным, быть очень похожим, довольно твердый, темный цвет, покрытие на поверхности, как... так и..., при работе с, в соответствии с, непроводник, в этом отношении, при надлежащих условиях, однопроцентный раствор, защитное по­ крытие, продлить жизнь
Ex. 8. Fill in the blanks with prepositions where necessary.