English for chemists

Lesson 6
ГРАММАТИКА: Составное именное сказуемое. Общие сведения о нелич­ ных формах шагала. Способы выражения предикатива.
Section I
Ex. 1. Pronounce the following words:

al + согласная _[°:1] call, also, all, small, already, almost,

always, ball, salt, although, wall

al + k
but:

a

but:
wh

but: wh + о w + a
w + ar
[*:) walk, chalk

• 
  alcohol, alkali, calcium, alchemist
  

_[a:] sample, example, past, after, answer, ask,

half, task, class, grass, glass, pass, vast,

mask, fast, last

• 
  mass
  

23. 
    what, while, when, where, which, white, why
    

lh] who, whose, whole, whom [WD] want, water, wash, was, watch [wo:] warm, war

b) light [laitj, ratio ['reijiou], committee [ko'miti], accuracy ['xkjorosi], deuterium [dju(:) 't юпэт], tritium ftntiom], nucleus [*nju:kli9s], ionize ['aianaiz],

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covalent [koo'veilont], convenient [kon'vi:njont], sulphuric [SAl'fjosnk], cathodc ['kxOaod], anode [’jcnood]
Ex. 2. Read the following words and say what Russian words help to understand their meaning:
mass, individual, calculate, committcc, standard, zinc, impress, isotopic, deuterium, tritium, radioactive, stable, ordinary, separation, electrolysis, concentrate, apparatus, proton, ion, sole, neutron, characteristic, general, natural, recombine, line, combination, organic, covalent, type, class, act, negative, molecule, hydride, barium, action, cathodc, anode
Ex. 3. Pay attention to the following way of word-building:
основа слова + -ize [aiz] —» глагол
summarize, organize, recognize, ionize, revolutionize, generalize
основа слова + -ем -» существительное, прилагательное
student, component, constituent, coefficient, opponent
different, convenient, intelligent, efficient, violent, evident, constituent
со- + основа слова -» существительное, прилагательное, глагол
co-worker, co-author, co-pupil, co-student, co-reactant, coordination
covalent, coaxial, coordinate
__________________coexist, cooperate, coagulate, coordinate_________
Ex. 4. Compare the meanings of the verb with and without prepositions. Use a dictionary if necessary.
come — come back— comc ofF— comc out; decide — decide upon; go— go back — go on— go away — go out — go in for; stand— stand up— stand for, make— make up— make out; find — find out; set— set up; give— give away— give back— give ofF— give up; get— get ofT— get out— get together— get up; consist in — consist of; use— use up
Ex. 5. Make up some sentences of your own illustrating different meanings of verbs with and without prepositions. Use the verbs from exercise 4.
Text 6 A
Hydrogen
Hydrogen is the lightest chcmical element. Its mass is die unit of measurement for the masses of other elements.

Atomic weight, or mass, was long considered the most important property of an clement. By weighing the amounts of individual elements making up a chcmical compound and calculating the weights of these ratios

to the weight of hydrogen which will combinc with the same elements, it is found that the atomic weights of the other elements are almost, but not quite, whole numbers.
During the nineteenth century a committee of chcmists was chosen to decide upon a standard of accuracy for atomic weights. The committee set the atomic weight of oxygen at 16.000 in order to make the atomic weights of other elements comc out closer to whole numbers. That change of standards gave hydrogen the weight of 1.008.
Hydrogen was first obtained in 1766 by Sir Henry Cavendish in London. He found that he could get the gas by dissolving zinc, iron or tin in diluted vitriolic acid (H2S04) or spirit of salt (HCI). He discovered that a mixture of hydrogen and common air explodes with a long noise, and he was impressed with the lightness of the gas. He named the gas “inflammable air”, the name “hydrogen” (water-former) was given by Lavoisier.
Hydrogen exists in three isotopic forms, known as hydrogen (or protium), deuterium and tritium. Tritium is radioactive, with a short half-life. Deuterium is stable, and occurs in a small amount with ordinary hydrogen. Its compound (D20 ) is known as heavy water. Slight differences between the properties of ordinary water and heavy water allow their separation, notably by electrolysis, in which ordinary water is decomposed and heavy water bccomcs concentrated in the water left in the apparatus.
The nuclear structure of ordinary hydrogen consists of one proton, the unit of matter. This is the same as a hydrogen ion. An electron as the sole planet in this system completes the structure of hydrogen atom.
The diffcrcncc between ordinary hydrogen and heavy hydrogen (deuterium) lies in the fact that deuterium has a neutron in the nucleus in addition to the proton. Addition of the neutron adds weight but docs not change the chcmical characteristics. This is in accordance with a general rule covering structures of elements.
Tritium has a nuclcus consisting of one proton and two neutrons. Hydrogen is given oiTby some natural gas wells, but it cscapcs into

the upper air. It is not found uncombincd on the earth. It is recognized in the stars by its spectrum lines in the light that wc receive from them.

In combination with oxygen, in the form of water, and with carbon, in the many organic compounds, hydrogen is one of the most abundant elements on the earth.
Hydrogen combines with other elements and forms different kinds of compounds, some of which ionize in solution, others which arc joined with covalent bonds, yielding organic types of compounds.
Although formerly it used to be classed with the alkali metals of Group 1 in the periodic table, hydrogen acts as a negative part of the molecule when it is in combination with those metals. It forms hydrides which arc in general colourless crystals. Similar compounds arc formed with calcium and barium of Group II. The hydrides decompose in water,

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releasing hydrogen. This properly has been used as a convenient way to store hydrogen.

Hydrogen is usually obtained by action of sulphuric acid (H2SO.«) on zinc. The metal replaces the hydrogen, which bubbles оПГ a gas. Electrolysis of water also liberates hydrogen at the cathodc, while oxygen comes off at the anode.

Words and Word-Combinations to Be Memorized
in accordance with, act, action, alkali, anode, apparatus, barium, bond, carbon, choosc, comc out, combine, concentrate, consider, covalent, decompose, difference, dissolve, electrolysis, clcctron, explode, form, general, give off, half* life, hydride, hydrogen, ion, ionize, line, measurement, molecule, negative, nucleus, in older to, ordinary, radioactive, separation, spectrum, stable, standard, sulphuric, tin, unit, whole, zinc
Ex. 6. Give the Russian equivalents for the following:
unit of measurement, make up a compound, whole numbers, a committee of chcmists, a standard of accuracy, in order to, weigh, dissolve, zinc, iron, a diluted acid, common air, the lightness of the gas, hydrogen, an isotopic form, radioactive, a short half-life, stable, a small amount, ordinary, heavy water, slight difference, electrolysis, apparatus, consist of, the unit of matter, an ion, an clcctron, complete the structure, the difference lies in the fact, in addition to the proton, change the chcmical characteristics, be in accordance with, a rule, a neutron, a proton, to give off, escape into the upper air, in the stars, spcctrum lines, different kinds of compounds, in solution, similar compounds, at the cathodc, at the anode
Ex. 7. Give the English equivalents for the following:
самый легкий химический элемент, единица измерения, самое важное свойство, целое число, для того чтобы, находить, получить газ, растворить, разбавленная серная кислота, обычный воздух, лег­ кий газ, изотопная форма, радиоактивный, короткий период полурас­ пада, химическое соединение, тяжелая вода, незначительные разли­ чия, электролиз, состоять из, находиться в соответствии с, общее правило, линии спектра, в виде воды, соединяться с другими элемен­ тами, различные соединения, ионизироваться в растворе, щелочные металлы, гидрид, разлагаться в воде, на катоде, на аноде
Ex. 8. Fill in the blanks with prepositions where necessary.