English for chemists

Lesson 18
ГРАММАТИКА: Придаточное предложение в функции подлежащего.
Scction I
Ex. 1. Practise your pronunciation.

1. 
   iodine [*aiodi:n], equilibrium [.i:kwi'libnom], fluidity [flo'iditi], viewpoint ('vjuipaint], process (‘prooses], agitate [*ad3iteit], vigorously fvigorosli], agitation [.ffigi'tei/on], thermal ['0з:то1], finally [Tainoil], cause (ko:z], relative [‘relotiv], regular ['regjolo], arrangement [a'reindsmont], instead [in'sted], regularity [,regjo'l
2. 
   '!iquid\iodine, andjheMiquid, arcjnucqui\librium, thcu'naturc of^a
   

\liquid, tow'stay)j'closejo\gether, the^'grouping^of \molecules
c) 'As a 'crystal is/heated. | its 'molcculcs are in'crcasingly agiNtatcd.

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Ex. 2. Pay attention to the structure оГ the following words. Translate them into Russian:

1. 
   somebody, someone, something, somewhere, somehow, somewhat, sometime, sometimes
   

2. 
   important, pleasant, abundant, resistant, brilliant, disinfectant, lubricant, significant
   
3. 
   freedom, kingdom, wisdom
   

Ex. 3. Define the meanings оГ the word point in the following scntcnccs:

1. 
   Point A on the graph corresponds to the boiling point of a solution.
   

2. 
   The reaction goes to completion when the temperature is kept in the range of25-30°C, this is a particularly important point. 3. At this point he stopped for a minute and then continued his explanation. 4. There arc different points of view concerning the hypothesis. 5. The inchingpoint of crystalline iodine is 114°C. 6. The proccss of melting can be described from the molccular viewpoint. 7. Up to this point everything was all right, but then something happened and the proccss became unstable. 8. It must be pointed out that only a crystal is characterized by regular anangemcnt ofatoms and molcculcs.
   

9. 
   It is a very interesting point, wc shall discuss it later.
   

Ex. 4. Find the predicate and the subject in the following sentences:

1. That the properties of liquid iodine and solid iodine arc different is quite obvious. 2. That the density of a liquid is less than that of a corresponding crystal can be easily explained. 3. How wc are to make measurements will be dear from the instruction. 4. Whether high pressure is ncccssary is to be known from the articlc.
Text 18 A
The Nature of a Liquid
When iodine crystals arc heated to U4°C, they melt forming liquid iodine. The temperature at which the crystals and the liquid arc in equilibrium — that is, at which crystals have no tendency to melt or the liquid has no tcndcncy to freeze— is callcd the melting point of the crystals, and the freezing point of the liquid. This temperature is I I4°C for iodine.
Liquid iodine differs from solid iodine (crystals) mainly in its fluidity. Like the solid, and unlike the gas, it has a definite volume (1 g occupics about 0.2 cm’), but it docs not have a definite shape: instead, it fits itself to the shape of the bottom part of its container.
From the molccular viewpoint the proccss of melting can be described in the following way. As a crystal is heated, its molcculcs arc increasingly agitated, and move about more and more vigorously, but at lower temperature, this thermal agitation docs not carry any one molecule any significant distance away from the position fixed for it by the arrangement of its neighbours in the crystal. At the melting point the agitation finally

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bccomcs so great that it causcs the molcculcs to slip by one another and to change somewhat their location relative to one anothcr. Thcy continue to stay close together, but do not continue to retain a regular fixed arrangement. Instead, the grouping of molcculcs around a given molcculc changcs continually, sometimes being much like the close packing of the crystal, in which cach iodine molcculc has twelve near neighbours, and sometimes considerably different, the molcculc has only ten or nine or eight near neighbours. Thus, a liquid, like a crystal, is a condensed phase, as contrasted with a gas, the molcculcs being piled rather closcly together; but whereas a crystal is characterized by regularity of atomic or molccular arrangement, a liquid is characterized by randomness of structure. The randomness of structure is usually the reason why the density of a liquid is somewhat less than that of the corresponding crystal.
W ords and W ord-Com binations to Be M emorized
away, bottom, characterize, considerably, container, contrast, differ from, differ in, distance, finally, fit, fix, freeze, increasingly, instead, mainly, melt, melting point, phase point, melting, random, regular, relative, shape, significant, sometimes, somewhat, stay, that is, thermal, viewpoint
Ex. 5. Give the Russian equivalents for the following:
be in equilibrium, the tcndcncy for crystals to melt, freeze the liquid, differ in properties, unlike the liquid, have a definite volume, instead, fit itself to the shape of, in the following way, carry away, changc somewhat, stay elose together, the elose packing of the crystal, considerably different, a randqm structure, the density of a liquid
Ex. 6. Give the English equivalents for the following:
naipcTb до, точка плавления вещества, отличаться от, иметь опре­ деленную форму сосуда, с точки зрения, изменить местоположение, ipynmtpoBKa молекул вокруг, ближний соссд, плотная упаковка, ха­ рактеризоваться чем-л., произвольное расположение молекул, не­ сколько меньше, каждая молекула йода, относительно друг друга, отличаться чем-л., в отличие от газа
Ex. 7. Fill in the blanks with prepositons where ncccssary.
1. Crystals ... iodine melt when they arc heated ... I14°C. 2. Liquid iodine differs ... solid iodine... its fluidity. 3. Usually, liquid fits itself...
the shape... the bottom spacc ... its container. 4. The proccss... melting can be described... the following way. S. This proccss is intcrcsing... the molccular viewpoint. 6. Regularity... atomic or molccular arrangement is characteristic ... a crystal. 7. A liquid is characterized ... randomness ...

structure. 8. A solid occupics ... a definite volume.

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Ex. 8. Translate the scntcnccs into Russian, paying attention to different functions of the words ending in -in g .
1. Crystals melt, forming liquid iodine. 2. The temperature at which the crystals and the liquid arc in equilibrium is callcd the melting point. 3. Freezing of a liquid is very interesting to observe. 4. Healing must be done in the following way. 5. The grouping of molcculcs around a given molecule changes by raising the temperature. 6. What arc you going to do now? 7. Attempts arc being made to synthesize new elements in laboratory.
Ex. 9. Translate the sentences into Russian.
1. Who is the discoverer of the periodic law is well known not only to specialists but practically to everybody. 2. That solid, liquid and gas arc the three main states of a substance is a matter of common knowledge. 3. Whether these substances will react depends on the conditions of the reaction. 4. Whether a solution is acidic or not may be easily shown using litmus paper. 5. That a particular substance contains one element or another may be determined by qualitative analysis. 6. That the vapour pressure of a crystal depends on its size is well illustrated by many experiments. 7. Whether water is a compound or not may be shown by the reaction between water and some metals. 8. What ancient scientists thought was based on what they could observe around them. 9. That the alchemical period was very important in the history of chcmistry is unquestionable.
10. That chain molcculcs can be many thousands of atoms in length affects the behaviour of these substances. 11. What number of protons is there in the nucleus of the clement is known from its atomic number. 12. That water will dissolve a great number of different substances is an interesting fact. 13. That at the early stages of its development chemistry was mostly descriptive in character was quite natural. 14. Who the discoverer of nitrogen was is well known, it was isolated by Rutherford. 1 5. That students of chcmistry should be able to write chcmical equations readily and accurately is highly important. 16. That it was A. M. Butlerov who introduced the term “chcmical structure” should not be forgotten. 17. That melting is a physical process must be quite clear to the student of chemistry. 18. Whether the hydrogen bond will be broken depends on the amount of energy. 19. Who will examine us in general chemistry is not known yet. 20. That the aim of scicncc is to explain things is a popular belief. 21. When the process started was not registered by the instrument. 22. What pressure should be applied should be decided before the experiment.
Ex. 10. Translate the sentences into English.
1. Как происходит переход из одного физического состояиия в другое, должно быть хорошо понятно каждому студенту. 2. Каждое вещество имеет свою собственную точку плавлення при одинаковом давлении. 3. Точка плавления твердого вещества— это в то же время и точка замерзания жидкости. 4. Известно, что жидкость принимает

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форму сосуда, в котором она содержится, но сс объем не зависит от объема сосуда. 5. В отличие от газа, у кристаллов и жидкостей моле­ кулы располагаются довольно близко друг к другу. 6. То что структу­ ра является одной из важнейших характеристик состояния вещества, необходимо помнить всегда. 7. Кристаллы имеют упорядоченную структуру, а структура жидкости произвольна, поэтому плотность жидкости несколько меньше, чем у соответствующего кристалла.
Ex. 11. Answer the following questions:
1. What temperature is callcd the melting point? 2. What is the difference between liquid and crystalline iodine? 3. In what way is it possible to explain the change from the solid to the liquid? 4. What is the principal difference between solid and liquid from the structural viewpoint? 5. What does the molccular motion depend on?