Part 2

Exercise 1. Read and translate the text.

The rusting of metals

It has long been known that metals can pass from a metallic to an earthy form. One must be careful not to expose unprotected iron to the open air, as under the influence of atmospheric conditions the outer layer of the iron quickly changes into a reddish crust called the rust. One can easily find that this new material differs from iron. The rust is very brit­tle, it is much lighter than iron and it is not at­tracted by a magnet. It was early observed that, although the specific gravity of the earthy product was less than that of the metal, yet there was a much greater bulk of it, and that, in fact, the earthy material weighed more than the original specimen of the metal.

It was Lomonosov who first proved that the extra material came from the air. He placed some tin in a flask and sealed up the mouth of the vessel. The tin was heated and converted into the white powder. Upon weighing the apparatus it was found that no change in weight occurred. It turned out, however, that when the mouth of the flask was opened, a good deal of air rushed in and the total weight was then greater. A portion of the original air had joined itself with the tin to form the powder.

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ighteen years later the same experiment was made and the same conclusion was drawn from it by Lavoisier. He named the gas taken from the air, oxygen. It is possible to confirm these conclusions in various ways. For example, when the air is pumped out of the flask before it is sealed, the metal can be heated in the vacuum indefinitely without rusting. Thus it can be seen that fundamentally rusting is the process in which metals oxidize and form compounds. It has been estimated that more than 25 % of the an­nual production of iron in the USA is consumed in replacing other iron that has been rendered unserviceable by rusting.

It is necessary, therefore, to wage a constant battle against this chemical process and our immediate concern is how to take care of metallic devices and structures once they enter our possession. We try to prevent or reduce rusting by various means, such as electroplating, painting or otherwise treating the metals that are susceptible to attack of this harmful action.

Vocabulary

rust - ржавчина, коррозия

light - легкий

specific gravity - удельный вес

specimen - образец

flask - колба

to seal - запечатывать

vessel - сосуд

powder - порошок

annual - ежегодный

Exercise 2. Answer the following questions.

1. What is your understanding of rusting?

2. What is the reason for rust?

3. What measures are taken to prevent rusting of metals today?

4. Who proved that the extra material came from the air?

5. Do you know any scientists in your country who are dealing with the problem of rusting?

Exercise 3. Put questions to the bold-typed words.

1. He placed some tin in a flask.

2. He named the gas taken from the air, oxygen.

3. Eighteen years later the same experiment was made.

4. The tin was heated and converted into the white powder.

5. A portion of the original air had joined itself with the tin to form the powder.

6. Upon weighing the apparatus it was found that no change in weight occurred.

7. The rust is much lighter than iron.

8. It is necessary to wage a constant battle against this chemical process.

9. When the mouth of the flask was opened, a good deal of air rushed in.

10. One can easily find that this new material differs from iron.

11. The rust is not at­tracted by a magnet.

12. It is possible to confirm these conclusions in various ways.

Exercise 4. Give the equivalents for the following words and make up sentences with them: vessel, flask, tin, metal, rust, powder, light, to prevent, air, annual, specimen, flask, device, to draw a conclusion.

Exercise 5. Match the beginnings of the sentences with the endings.

1. Oxygen is a a) reduce rusting by various means.

2. Upon weighing the material b) was about 25 % .

3. Annual production of cast iron c) gas taken from the air.

4. W

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   e have obtained d) we have determined its composition.

5. The rust is e) a white powder.

6. The metal f) very brittle.

7. We prevented to g) was heated.

8. This experiment h) from iron.

9. This new material differs i) was made again.

Exercise 6. Guess the concept based on the definition.

1. A chemical compound which is usually a liquid that contains hydrogen and has pH of less than seven.

2. A colorless gas that is present in water and air and is necessary for people, animals, plants to live.

3. A hot bright steam of burning gas that comes from something is on fire.

4. A metal that is formed by mixing two types of metals together.

5. A chemical change produced by two or more substances acting on each other.

6. A substance which is used to cause chemical reaction.

Exercise 7. Make the following sentences negative and interrogative.

1. Eighteen years later the same experiment was made and the same conclusion was drawn from it by Lavoisier.

2. He named the gas taken from the air, oxygen.

3. The rust is very brit­tle.

4. This colorless gas is present in water.

5. A portion of the original air had joined itself with tin to form the powder.

6. We try to prevent or reduce rusting by various means.

7. It was Lomonosov who first proved that the extra material came from the air.

8. It has long been known that metals can pass from a metallic to an earthy form.

9. It is possible to confirm these conclusions in various ways.

Exercise 8.:

1. Grammar quiz: find and correct the mistakes:

1. When the air was pumped out the flaks was sealed.

2. While I watched TV, she did her homework.

3. When I returned home she went away.

4. When vegetation decomposed peat was formed.

5. Before I went to London I learnt English.

2. Divide the following sentences into a few simple sentences:

1. It is necessary, therefore, to wage a constant battle against this chemical process and our immediate concern is how to take care of metallic devices and structures once they enter our possession.

2. Eighteen years later the same experiment was made and the same conclusion was drawn from it by Lavoisier.

3. Paraphrase the following sentence: It was Lomonosov who first proved that the extra material came from the air.

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