Объясните разницу между физическими и химическими превращениями на английском языке.

A chemical change is a change that takes place in a substance, during which it breaks up into simpler substances or it combines with other substances to make a new one with different properties or characteristics. For example, mercuric oxide may be changed to mercury and oxygen by heating it; the burning of wood is an example of a chemical change in which the elements carbon and oxygen are combined to form the gas, carbon dioxide.
A physical change is one in which the identifying characteristics or properties of the substance are not changed although a change in form or state may occur. The melting of ice, the breaking of glass, or the dissolving of sugar in water are examples of physical changes.

 

Разделите следующие превращения на физические и химические.

1. Melting of ice. 2. Souring of milk. 3. Rusting. 4. Dissolving of sugar in water. 5. Separating the pigments of grass by chromatography. 6. Burning wood.

 

Test 3

1. Pottery, brick and porcelain with glass provide the class of materials known as…

a) non-metals

b) ceramics

c) metals

d) alloys

 

 

2. Ceramic materials are … in weight.

a) light

b) heavy

c) strong

d) durable

 

 

3. The … of application of products made from clay is very wide.

a) range

b) form

c) class

d) area

 

 

4. Silicate materials … glass, porcelain, enamels and cement.

a) form

b) use

c) consist of

d) include

 

 

5. The ceramic materials … from rock or clay mineral.

a) compound

b) were compounded

c) are compounded

d) have compounded

 

6. The ceramics … as building materials since ancient time.

a) have used

b) used

c) are used

d) have been used

 

 

7. Some ceramic materials can … steel.

a) form

b) cut

c) provide

d) cast

 

 

8. The making of steel depends on the … of ceramics

a) use

b) form

c) property

d) bond

 

 

9. The large oxygen atoms … as a matrix with small metal allows.

a) create

b) serve

c) influence

d) produce

 

 

10. Many articles made of ceramics provided man with …

a) products

b) materials

c) compounds

d) tools

 

 

Unit 4

 

I. Почитайте и переведите текст

 

Molecules are too small and are not seen under the most pow­erful microscope, but the movement of molecules can be made more real by a study of the so-called Brownian movement. Robert Brown, a botanist, observed in 1827 that small solid particles suspended in a liquid were in continual movement.

Matter can occupy three different states — gas, liquid and solid. Changes of state depend on the motion of sub-microscopic particles. The motion of these particles depends on energy. Cooling particles takes away energy and slows them down. Heating particles adds energy and speeds them up.

In fact the chief characteristic of matter isits eternal restlessness, and the degree of restlessness is determined by the stale of matter under observation; i.e. whether it be solid, liquid or gas. In gases molecules lead more or less independent existence and are moving with high speed in all directions; and the molecules must be continually colliding with each other and striking the walls of the vessel, and so exert pressure. A gas, therefore, has no definite shape or volume, and can be readily compressed.

We use gases, such as a natural gas, in many important ways. Cooling a gas into a liquid decreases its volume dramatically. This makes it possible to store and transport it more ef­fectively.

The molecules of a liquid can move sufficiently freely and allow the liquid to take up the shape of the vessel; but the attractive forces between the molecules, which are much closer together and moving more slowly than in a gas, do not permit the liquid to be compressed to any extent nor to vary its volume. A liquid, therefore, has a definite volume but not fixed shape, and is slightly compressible. In solids the freedom of the molecules must be very restricted and their motion is probably confined to small oscillations only, and must be greatly hampered by the nearness of neighbouring molecules. A solid, therefore, has both definite shape and volume, and is very difficult to compress.

Crystals are highly ordered form of solid matter. They were one of the first clues to the arrangement of particles in the solid state.

The rates of motion of molecules have an important influence on chemical changes. They occur most readily when molecules are moving freely, i.e. in gases; and chemical activity is least pronounced in solids, where the movement of molecules is slight.

The states of matter are few. But the ways in which they are real­ized, the number of different substances around us, are many. Let me give you an example. On breathing oxygen — the life-giver — is obvi­ously a gas. But here is another element, sulphur that chemically very closely related to oxygen. And yet, it is obviously different: it is a solid at room temperature. Now, there are obviously different forces that work between the atoms of molecules of sulphur and oxygen within these two substances. We want to know why this is so. We have to probe deeper, we have to, then, ask: What is the nature of the atom? What is it that makes oxygen and sulphur similar or different?

 

Vocabulary

1. confine – ограничивать
2. continual – непрерывный; постоянный
3. hamper – препятствовать, затруднять, мешать
4. hardly – едва
5. neighbouring – соседний
6. observe – наблюдать
7. occur – происходить, встречаться
8. oscillation – колебание
9. pressure – давления
10. probably – возможно
11. readily – легко, охотно
12. restlessness – подвижность; беспокойство
13. restricted – ограниченный
14. slight – незначительный
15. suspend– вешать, подвешивать
16. therefore – следовательно
17. vessel – сосуд

 

II. Выполните упражнения

1. Составьте 15 вопросов к тексту
2. Найдите английские эквиваленты к русским сочетаниям

1. мощный микроскоп

2. постоянное движение

3. под наблюдением

4. независимое существование

5. высокая скорость

6. сила притяжения

7. изменять объем

8. постоянная форма

9. оказывать давление

10.друг с другом

 

a. under observation

b. independent existence

c. high speed

d. continual movement

e. powerful microscope

f. with each other

g. to exert pressure

h. the attractive force

i. to vary one's volume

j. a fixed shape

1. Прочитайте, переведите однокоренные слова и определите, к какой части речи они относятся

observe, observation; rest, restless, restlessness; suspend, suspen­sion; collide, collision; hard, hardly, hardness; power, powerful; at tract, attractive, attraction; compress, compressible

 

4. Переведите следующие предложения и используя данные фразы, выполните задания

 

As for as I know/understand
According to the text

As for as … is concerned

 

It’s interesting to know/to find out

To my mind
I have a feeling
Give an account of the characteristic properties of matter in the solid, liquid and gaseous states.

What is meant by the statement "the eternal restlessness of matter"?

Give an example of the "Brownian movement". What light do your examples throw upon the nature of matter?

 

1. Составьте свой диалог, используя информацию текста, на одну из следующих ситуаций

- Two student are discussing the lecture about matter

- A student discussed his/her paper with the supervisor

 

III.Control text

 

Прочитайте и переведите текст

 

That matter may exist in three physical states (solid, liquid and gas) is common knowledge. It is usually possible to change matter from one state to the other by changing its temperature. For instance, a piece of ice is called a solid; it may melt and form a liquid; as it evapo­rates, liquid water changes into a vapour, i. e. into the gaseous state.

Many kinds of matter, like water, can be obtained in each of the three states; for some, however, extraordinary means have to be used in order to produce one, or even two of the states; and for others, only two states are known or can be produced.

Common salt, for example, exists normally as a solid; at a temper­ature of several hundred degrees, it can be liquefied; and at still higher temperature it is converted into vapour. Carbon, a solid under normal conditions, can be vaporized, but it has never been liquefied.

Solids have both a definite volume and a definite shape. Liquids, too, have a definite volume, but they take the shape of their containers.

Gases have neither a definite shape nor a definite volume. A chemist must have a thorough knowledge of the states of matter and of physical laws that govern the behaviour of matter in various states.

That all matter is composed of molecules is known to everybody. The question which must be answered, then, is: if all matter is com­posed of molecules, what is the essential difference between the states of matter? The answer to this question is that the essential difference between these states is the relative quantities of energy molecules possess in different states.

 

Ответьте на вопросы, используя информацию текста

1. What is the difference between a thing and a stuff?

2. Can you tell a thing from a stuff: brass, bottle, atmosphere, chair, pan, boiled egg, glass, ornament, wood, sea water, air, plastics, toy soldier? Match a thing with the stuff it is made of.

3. Can we call a stuff matter? Explain why.

Test 4

 

1. Matter is not only … animals and plants

1. Unloving
2. Living
3. Converting
4. Occurring

2. Matter is constantly undergoing …

1. Forms
2. Mixtures
3. Classes
4. Changes

3. Forms of matter may change, but matter itself is neither … not created

1. Improved
2. Appeared
3. Destroyed
4. Referred

4. The … theory explains what matter is built of

1. Dalton
2. Experimental
3. Molecular
4. Atomic

5. The movement of molecules … by Robert Bromn

1. Was studied
2. Studied
3. Has been studied
4. Had been studied

6. The molecules of a … can more freely

1. Gas
2. Matter
3. Liquid
4. Solid

7. The motion of particles … energy

1. Refer do
2. Depends on
3. Consist of
4. Slow down

8. Sulphur is chemically very closely related to …

1. Oxygen
2. Hydrogen
3. Carbon
4. Rater

9. The states of matter are …

1. Few
2. Many
3. Some
4. Any

10. Cooling a gas into a liquid makes it possible … it more effectively

1. To keep
2. To use
3. To hold
4. To store

 

Unit 5

 

I Прочитайте и переведите текст

 

Radioactivity

The discover of natural radioactivity by the French researcher Henri Becquerel ushered in a new era in science and technology. This phenomenon is based on the principle that substances occurring in nature, such as uranium and radium, are transformed into other chemical elements, independently of influences from outside, emitting different kinds of radiation which blacken a photographic plate as this is done by the rays of light.

In the decades following this discovery thousands of scientists in many countries of the world have systematically investigated the essence and the application of radioactivity and of the radiation emitted by radioactive nuclides.
The basic practical and theoretical work done by the Curies, the work by E. Rutherford who achieved an artificial nuclear transformation, the development of apparatus for the detection of radioactive nuclides by Geiger and Muller, the discovery of neutron by the English physicist J. Chad-wick, the discovery of the artificial radioactivity by the Curies and the discoveries of some other scientists are the milestones in the history of radioactivity.
The field of application of radioactive nuclides in chemistry, physics, biology, agriculture, medicine and industry has rapidly expanded.
One of the most interesting fields of applications of radioactivity is the determination of the age of carbonaceous materials, that is materials containing carbon, by measurement of their radioactivity due to carbon 14.
This technique of radiocarbon dating permits the dating of samples containing carbon with an accuracy of around 200 years.
At the present time the method involved can be applied to materials that are about 25,000 years old.
Today the range of application of radioactive nuclides comprises all branches of research work. Thus, for example, certain medical examinations call for short lived radioactive nuclides in order that the human organism should not be exposed too long a period of time to radiation, whereas a radioactive nuclide which excites the luminescent material should have a long half-life.
Investigations into the reaction mechanisms in chemistry, researches in the field of physics, the explanation of vital processes in plants, animals and man, diagnostics of diseases of the human body, the testing of metallic and ceramic materials are but a few fields of science and technology which today, 91 years after the discovery of radioactivity, cannot dispense with radioactive nuclides and the radiation emitted by them.
It should be added that a considerable number of research problem's has only become soluble by the use of radioactive nuclides.

 

Vocabulary

1. application – применение
2. to emit - излучать
3. ray – луч
4. to occur – происходить
5. artificial – искусственный
6. milestone – веха
7. to measurement – измерение

 

8. to permit – позволять
9. sample – образец
10. to comprise – охватывать
11. investigation – исследование
12. disease – болезнь
13. soluble - разрешимый
14. vital – низший
15. to expose – подвергать

 

 

II Выполните упражнения

1. Ответьте на вопросы

1. Who discovered the phenomenon of radioactivity? 2. What is the phenomenon of radioactivity based on? 3. What are the milestones in the history of radioactivity? 4. Where can radioactivity be applied? 5. What is the most interesting field of applications of radioactivity? 6. Where are radioactive nuclides applied now?

 

2. Откройте скобки, выбрав правильную форму предлога, объясните почему и переведите предложения.

1. A positively (charging, charged) particle having the mass of the electron was discovered in 1932. 2. The scientist found that X-rays (produced, producing) were complex. 3. According to this theory (dealt with, dealing with) atomic structure the nucleus is a very small, compact, central part of an atom. 4. Oppositively (charged, charging) particles exert forces of attraction on one another. 5. Elements (composed, composing) of atoms containing only one or two valence electrons usually form positive ions. 6. (Investigated, investigating, having investigated) this phenomenon the scientists can make some important conclusions. 7. The work (doing, done) by these research-workers resulted in many new discoveries. 8. The ions (involving, involved) can be used as a highly sensitive detector of radiation. 9. The investigation (followed, following) by many experiments was of great importance. 10. The nuclei (formed, forming) in this reaction are unstable.

3. Переведите предложения, объясните значение глагола «to hare».

1. The laboratory of general chemistry has many benches with a number of drawers. 2. A first-year student has to carry out a number of experiments in the laboratory of general chemistry. 3. This term the students have carried out a number of experiments. 4. These substances have very low solubility. 5. They have to find out the solubility of this substance. 6. They have found the solubility of this substance and now can investigate its properties better. 7. This metal has found wide application both in industry and in agriculture. 8. They have to raise the temperature greatly as the mixture doesn't boil. 9. Hydrogen peroxide has been heated. 10. Hydrogen peroxide has a lower vapour pressure than water.
11. The evaporation has to be carried out in the water bath. 12. This crucible has been used for heating some solutions. 13. This solution has an unpleasant odour, he has to open the window. 14. A rombic sulphur has to be kept at a temperature of 96°C. 15. It is necessary to purify water, you will have to pass it through porous paper. 16. It has to be noted that chlorine dioxide reacts with water and yields a mixture of chlorous and chloric acid. 17. It has been already noted that hydrogen is found in the free state only in minute quantities.

4. Поставьте все типы вопросов к предложениям, переведите предложения

1. Much could be (writing, written) about the application of nuclides. 2. Many experiments have been (carrying out, carried out) in the field of radioactivity. 3. The work (doing, done) by the scientists was of great significance. 4. Many of the above-mentioned applications of radioactive nuclides or of the radiation (emitting, emitted) by them are directly or indirectly connected with industry. 5. A mechanical method was (substituting, substituted) by a new one. 6. This type of radiation consists of a current of positively (charged, charging) particles. 7. This discovery (following, followed) by many experiments was of great use to chemists. 8. The two substances (investigating, investigated) were homogeneous. 9. The man (speaking, spoken of) was thе first to discover this phenomenon.

5. Сделайте письменный пересказ текста на английском языке

III. Control text

Прочитайте и переведите текст

Radiation exerts two opposing effects on polymers. On the one hand, it breaks up the polymer molecules into smaller pieces. On the other, it causes liberation of a hydrogen atom from each of the two adjoining molecules with formation of a link between the two molecules (cross-linking). The existence if cross-links in a polymer makes the material tougher and higher melting and is very desirable for certain applications.

The cross-linking of polymers by radiation has been much studied. The irradiation of any organic compounds results in breaking of CH bonds, leaving free bonds on the carbon atoms while the hydrogen atoms go off together in pairs to form hydrogen gas. In a liquid the resulting free radicals can diffuse as a whole through the solution and eventually meet together and combine. In a solid polymer it is not clear how these centers get together. One proposed mechanism is that a hydrogen atom from a neighbouring carbon will pop into the vacated hydrogen space, producing a new free bond on the atom adjacent to the original free bond position. This process will continue, with the free bond flowing up and down the chain, until the free bond happens to find itself next to a free bond formed on the adjacent molecule which is likewise traveling up and down. Another mechanism, possible perhaps only with amorphous polymer, is that the long-chain molecules as a whole may move with respect to one another until the free bonds find themselves in proximity.

Whatever the mechanism of cross-linking may be, the result is of commercial value.

Озаглавьте текст и объясните свой выбор. Напишите 5 предложений, передающих основное содержание текста.

Test 5

 

1. The nuclei of hydrogen and oxygen are absolutely…

Large

Strong

Stable

Weak

 

2. The Curies discovered the … radioactivity

1. Artificial
2. Nuclear
3. Natural
4. Uranium

 

3. The discovery of radioactivity … а number of questions.

Rise

Raised

Rose

Raise

 

The discovery of natural radioactivity … by Henry Becquerel

1. Was being made
2. Was made
3. Has been made
4. Had been made

 

The field of application of radioactive nuclides has rapidly…

1. Increased
2. Improved
3. Discovered
4. Expanded

 

Uranium and radium are … into other chemical elements

1. Transformed
2. Emitted
3. Based
4. Done

 

Blackening a photographic plate is done by the … of light

1. Ways
2. Atoms
3. Rays
4. Movement

 

Radiation exerts two opposing effects on …

1. Elements
2. People
3. Atoms
4. Polymers

 

The irradiation of organic compound … in breaking of CH bonds

1. Leads
2. Continue
3. Results
4. Makes

 

The range of application of radioactive nuclides … all branches of research work

1. Includes
2. Comprises
3. Consists
4. Makes

Unit 6

I. Прочитайте и переведите текст

There is a tradition among physical chemists to regard the properties of liquids as essentially invariant. When comparing them with gases we can see that they are only slightly com­pressible.

Having carried out a number of investigations the scien­tists made a very interesting discovery, i.e. a new stable form of water having the density almost one and a half times that of ordinary water was obtained. This water was named Water II. Having examined its properties they found out that its index of refraction was equal to about 1.48 to 1.49. But when Water II was diluted with ordinary water (Water I) this value dropped to the value for pure water, i.e. 1.33. Having contin­ued their work the scientists stated that the density of Water II was equal to that of pure water. Then it was very important to learn the stability of the molecules of Water II and the forces responsible for their stability.

Some scientists suggested the possibility that on Venus wat­er exists mainly in the form of Water II. This question attracted the attention of many scientists and will be discussed in future.

Water is hydrogen oxide, a compound of hydrogen and oxy­gen. It can be made if hydrogen or a hydrogen-containing substance are burnt in air or oxygen.

Most of the world's water is liquid, but an important frac­tion is solid as ice and snow.

Many mineral substances contain water of crystallization (e.g. copper sulphate) and in the atmosphere there are millions of tons of water vapour. Clouds consist of minute droplets of water or crystals of ice.

Water dissolves a very large number of substances and is the most important solvent. It does not dissolve greasy, fatty substances or most plastics.

Having found the composition of water, the scientists could Investigate its properties. It was stated that ordinary water is impure, it usually contains dissolved salts and dis­solved gases, and sometimes organic matter.

For chemical work water is to be purified by distillation. Pure water is colourless, tasteless and odourless. Rain water formed by the condensation of water in the air is nearly pure water, containing only small propoftions of the dust and of dissolved gases.

Having examined the properties of water, the chemists found that physical properties of water can be used to define many physical constants and units.

The freezing point of water (saturated with air at 1 atm pressure) is taken as 0°C and the boiling point of water at 1 atm is taken as 100°C.

The unit of volume in the metric system is chosen so that 1 ml of water at 3.98°C (the temperature of its maximum density) weighs 1.000 g/cm³.

So water is one of the most important of all chemical sub­stances. It is a major constituent of living matter and of the environment in which we live.

Vocabulary

1. superdence – сверхплотная
2. to regard – рассматривать
3. hence – следовательно
4. negligible – незначительный
5. to compare – сравнивать
6. slightly – слегка
7. vit (namely) – а именно
8. choice – выбор

 

9. to cause – быть причиной
10. stable – постоянный
11. to dilute – растворять
12. to drop - капать
13. to assume - предполагать
14. impact – влияние
15. to burn – жечь, сжигать
16. to purity – очищать
17. to saturate - насыщать
18. to choose – выбирать

 

II. Выполните упражнения

1. Дайте русские эквиваленты к следующим словам, словосочетаниям и химическим терминам. Где конкретно они используются в тексте, а какие нет?

nouns: 1. condition, 2. current, 3. hydrogen oxide, 4. importance, 5. point of view, 6. quarter, 7. surface, 8. vapour

verbs: 9. burn, 10. cool, 11. cover, 12. heat

adjectives: 13. artificial, 14. dangerous, 15. marked, 16. strict

adverbs: 17. commonly, 18. exactly, 19. in this way

conjunctions: 20. either... or.

2. Подберите к словам из упр. 1 синонимы, данные ниже

a) to warm up к) water

b) usually 1) viewpoint

c) stream m) synthetic

d) steam n) to fire

e) to chill o) rigorous

f) hazardous p) to hide

g) the 4th part of a whole q) significance

h) noted r) the outer part

i) state s) precisely
j) thus

3. Найдите антонимы в А и В

А В

1. the commonest a) impossible

2. like b) the most unusual

3. simple c) old

4. usually d) common

5. new e) few

6. single f) eptionally

7. many g) to lose

8. decomposition h) natural

9. to obtain i) unlike

10.possible j) integration

11.easy k) complicated

12.dangerous 1) secure

13.artificial m) lenient

14.strict n) difficult

4. Откройте скобки, выбрав правильную форму предлога, переведите предложения

1. When (heating, having heated) this substance, one should be very careful. 2. (Investigated, having investigated, investigating) all the properties of new water, they could understand the mistery of silvery clouds. 3. The (dissolving, dissolved, having dissolved) materials may be soluble solids, liquids or gases. 4. Water (using, used, having used) in steam boilers, should be free from substances that cause corrosion. 5. (Purified, having purified, purifying) the water from the substance that cause corrosion, we can use it in steam boilders.

5. Поставьте 15 вопросов к тексту

III. Control text

Прочитайте и переведите текст

One of the most striking properties of water is its ability to dissolve many substances, forming aqueous solutions. Solutions are very important kinds of matter – important for industry and for life. The ocean is an aqueous solution that contains thousands of components: ions of the metals and non-metals, complex organic ions, many different organic substances. It was in this solution that the first living organisms developed, and it was from it that they obtained the ions and molecules needed for their growth and life. In the course of time organisms that were evolved could leave this aqueous environment, and move out onto the land and into the air. They achieved this ability by carrying the aqueous solution with them, as tissue fluid, blood plasma, and intracellular fluids containing the necessary supply of ions and molecules.

The properties of solution have been extensively studied, and it has been found that they can be correlated in large part by some simple laws.

Water not only is the most widely used of all solvents, but also, of all liquids, it most nearly approaches being the “universal solvent”. Every substance is probably soluble in water to some extent, although in many cases the solubility is so small that it is almost imperceptible. Thus, a saturated solution of barium sulphate contains less than a quarter of a milligram of solute per litre, and the solubility of silicon dioxide (quartz) – is even smaller than this. Yet, water that is allowed to remain for a long time in a quartz vessel must eventually become saturated with quartz; a saturated solution of this substance is so extremely dilute, however, that many litres of it would have to be evaporated to dryness in order to yield a visible residue. Such substances as barium sulphate, silver chloride, quartz, glass, mercury, and cellulose are usually considered as “unsoluble” in water; but this term, it must be remembered, is merely a relative one, and it would be more accurate to say that their solubility is exceedingly small.

 

-Передайте основное содержание текста в нескольких предложениях.

-Прочтите предложения и скажите, соответствуют ли они содержанию текста. Если нет, исправьте их.

1. Water can dissolve a great number of substances. 2. Solutions arc important in industry, but not in life. 3. A lot of components are dissolved in the ocean water.

4. The first living organisms developed in water and on the land and then moved into the air. 5. There are no laws common to all the solutions and the properties of each solution are studied separately. 6. Every substance is soluble in water to some

 

Test 6

1. One of the way to purity water is … it

1. to heat
2. to boil
3. to evaporate
4. to distillate

 

 

2. Water is the most … compound

1. usable
2. abundant
3. universal
4. pure

 

 

3. The ground water contains a great deal of …

1. impurities
2. mixtures
3. microbes
4. salts

 

 

4. When water vapour condences to liquid water, energy …

1. releases
2. will release
3. has released
4. is released

 

 

5. Water is a major … of living matter

1. constituent
2. part
3. form
4. substance

 

 

6. Water … a very large number of substances

1. evaporates
2. saturates
3. dissolves
4. drops

7. … water is odourless and tasteless

1. ground
2. pure
3. distillated
4. sea

 

 

8. Natural water have taste because of the presence of … substances

1. purified
2. distillated
3. evaporated
4. dissolved

 

 

9. Several common units of measurement … in terms of the properties of water

1. are used
2. are made
3. are defined
4. are discovered

 

10. Most of the world’s water is …

1. liquid
2. solid
3. gaseous
4. vapour

 

Unit 7