2015-05-13
461
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.
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.:
a) 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.
b) 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.
c) Paraphrase the following sentence: It was Lomonosov who first proved that the extra material came from the air.
