English for chemists

part of the Universe. 2. One of the most valuable parts of the chcmical theory is the periodic law. 3. Hard alloys arc applied to the surfaces of metal parts, increasing the life of the parts many times. 4. The substances taking part in the reaction should be pure. S. Partly, you can find the necessary information in this monograph. 6. V. Tikhonov played the part of Bolkonsky

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in llic IVar.and Peace. 7. They parted at 6 o’clock. 8. The firm was only a partial success. 9. Under certain conditions, hydrogen atoms in this compound may be in part substituted by sulphur.
Ex. 4. Find the predicate, the subject and the object in the following sentences:
1. In the nineteenth ccntury the valcncc bond was represented by a line drawn between the symbols of two chcmical elements. 2. Lewis’ paper written in 1916 is considered to be the basis of the modern electronic theory of valcncc. 3. These ideas were further developed by many investigators.
Text 19 A
The Study of the Structure of Molecules
The study of the structure of molcculcs was originally carried on by chcmists using methods of investigation that were essentially chemical in nature, relating to the chcmical composition of a substancc, the existence of isomers, the nature of the chcmical reactions in which a substancc takes part and so on. From the consideration of facts of this kind Frankland, Kckulc, Coupcr and Butlerov were led a ccntury ago to formulate the theory of valcncc and to write the first structural formulas for molcculcs, van’t Hoff and le Bel were led to bring classical organic stereochemistry into its final form by their brilliant postulate of the tetrahedral orientation of the four-valcncc bonds of the carbon atom, and Werner was led to his development of the theory of the stereo­ chemistry of complex inorganic substanccs.
In the nineteenth ccntury the valcncc bond was represented by a line drawn between the symbols of two chcmical elements, which expressed in a concisc way many chcmical facts, but which had only qualitative significance with regard to molccular structure. The nature of the bond was completely unknown. After the discovery of the clcctron, numerous attempts were made to develop an electronic theory of the chcmical bond. These culminated in the work of Lewis, who in his 1916 paper, which forms the basis of the modem electronic theory of valcncc, discussed not only the formation of ions by the completion of stable shells of electrons but also the formation of a chcmical bond, now callcd the covalcnt bond, by the sharing of the two electrons between two atoms. Lewis further emphasized the importance of the phenomena of the pairing of unshared as well as of shared electrons and of the stability of the group of eight electrons (shared or unshared) about the lighter atoms. These ideas were then further developed by many investigators; the work of Langmuir was especially valuable in showing the great extent to which the facts of chemistry could be coordinated and clarified by the application of the new ideas. Many of the features of the detailed theory that is discusscd were suggested in the papers of Langmuir and others written in the dccadc

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following 1916, or in (he book Valence and Structure o f Atoms and Molecules written by Lewis in 1923.
All of these early studies, however, contained, in addition to suggestion that have sincc been incorporated into the present theory, many others that have been discarded.
W ords and Word-Combinations to Be M emorized
complex, consideration, coordinate, dccadc, discard, discuss, draw, cspccially, essentially, formation, incorporate, lead to, line, numerous, originally, paper, phenomenon, with regard to, relate, and so on, stability, stable, structural, take part, valence, valuable
Ex. S. Give the Russian equivalents for the following:
cany on the study, essentially chcmical in nature, take part in a reaction, from the consideration of facts, formulate the theory of valcncc, structural formulas for molcculcs, final form, tetrahedral orientation of the bonds, represent the bond by a line, draw a line between, have qualitative significance, with regard to molccular structure, form the basis of a theory, share the electrons between the atoms, the features of the detailed theory, be incorporated into
Ex. 6. Give the English equivalents for the following:
изучение структуры молекул, методы исследования, первоначаль­ но, химический состав, существование изомеров, природа химичес­ кой реакции, и так далее, принять участие в реакции, такого рода факты, столетие тому назад, написать структурную формулу, четыре валентные связи атома углерода, теория стереохимии, провести ли­ нию, многочисленные попытки, сделать попытку, развить теорию, электронная теория валентности, образование химической связи, ко­ валентная связь, поделить электроны между чем-л., подчеркнуть зна­ чение чего-л., применение новых идей, предложить теорию, кроме, первые исследования
Ex. 7. Fill in the blanks with prepositions where necessary.

1.

Early chcmists carried ...

the study ...

the structure ...

molcculcs

... the methods that were essentially chcmical

... nature. 2. The first

structural formulas ...

molcculcs were written ...

more than a ccntury

ago. 3 ....

the 19th ccntury the valcncc bond was represented ...

a line

... the symbols ...

two chcmical elements. 4.

The nature ... the bond

was completely unknown. 5. ...

the discovery

... the electron attempts

were made to develop an electronic theory ...

the chcmical bond. 6 ....

1916 Lewis formed ... the basis ... the modem electronic theory ...

valcncc. 7. Early studies contained ... some suggestions that were discarded later.

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Ex. 8. Translate the scntcnccs into Russian, paying attention to different functions of the word regard.
1. At the beginning of the 19th century, atoms were regarded as the smallest constituent particles of matter. 2. Equal volumes of gases arc stated to contain the same number of molcculcs at the same temperature and pressure, regardless of composition. 3. Unfortunately, it’s not always that the young have great regard to their parents. 4. Particular attention must be paid to the chaptcr regarding the conditions of synthesis. 5. Many chcmical facts were described which had only qualitative significance with regard to molccular structure. 6. The work of Lewis was most important as regards the development of the electronic theory of valence.
Ex. 9. Translate the sentences into Russian.

1. 
   1. These results arc not in agreement with the theory. 2. They did their work in time. 3. Register the readings and then begin the calculations.
   

4. 
   Put the burner on the table. 5. The discovery of the electron stimulated the development of an electronic theory. 6. The information was given to a numerous audicncc. 7. The rate of the reaction often depends on the temperature. 8. The heating resulted in the explosion. 9. Give this instruction to the students. 10. Give the students this instruction.
   

11. 
    Lowering the temperature of a liquid lessens the kinetic energy.
    
12. 
    Hydrogen-has 3 isotopes. 13. The study of the structure of molcculcs has been carried on by scientists sincc early times..
    
    2. 
       I. Have you seen him? 2. Did you speak to her yesterday? 3 .1 don’t know anything about the author of this monograph. Do you know anything about him? 4. It is a very good apparatus, everybody likes to work with it.
       

4. 
   The bottle with H2S04 is on that shelf, bring it, please. 6. The temperature must be 25°C, don’t forget it. 7. They think it necessary to attend all the seminars. 8. The teacher made it dear that the examination will be difficult to pass. 9. Avogadro’s principle let one calculate the number of molcculcs per gram mole of a gas. 10. Chemistry helps one to understand other fields of scicncc better. 11. The properties of HC1 make it a useful laboratory reagent. 12. Consideration of all the facts enabled us to draw a very important conclusion. 13. They don’t think it possible to work with this substancc, it is not pure enough.
   

Ex. 10. Translate the scntcnccs into English.

1. 
   Проблема структуры молекулы давно интересовала химиков.
   

2. 
   Структурная формула — это формула, которая показывает, как сгруппированы элементы и как распределяются связи в молекуле.
   
3. 
   Бутлеров был первым из русских ученых, кто написал структур­ ную формулу. 4. В XIX столетии валентную связь представляли ли­ нией, которую проводили между символами двух химических эле­ ментов. 5. Природа связей тогда была совершенно неизвестна, б. При изучении структуры молекул было открыто существование изомерии.
   

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7. Изомеры — это соединения, которые имеют одну и ту же молеку­ лярную формулу, но разные структуры.
Ex. 11. Answer (he following questions:
1. Whal methods were used in the first investigations of the structure of molcculcs? 2. What do you know about isomers? 3. Who formulated the theory of valcncc? 4. What is particularly interesting as regards the valcncc bonds of the carbon atom? 5. In what way was the valcncc bond represented? 6. How did the discovery of the clcctron affcct the development of an electronic theory? 7. What do you know about the work of Lewis?