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