Text 2: d. I. Mendeleyev

D. I. Mendeleyev, the great Russian chemist, was born in Siberia on the eighth of February, 1834. When he was seven years old, he went to gymnasium in Tobolsk. He studied very hard, he especially liked mathematics, physics and history. At the age of 16 he entered the Pedagogical Institute in St. Petersburg, physico-mathematical department. He graduated from the Institute in 1855 and began teach chemistry at the Technological Institute and then at the University. In 1865 Mendeleyev was granted the Doctor of Science Degree for the thesis on the combination of alcohol with water. This work was both of great theoretical and practical significance. Soon after that D. I. Mendeleyev was appointed Professor of General Chemistry of St. Petersburg University. Besides lectures and supervision of the laboratory, D. I. Mendeleyev carried out great research work.

Mendeleyev’s greatest discovery wasthe Periodic Table. The Periodic Law suggested by Mendeleyev stated that the properties of the elements were a periodic function of their atomic masses. He presented the work to the Russian Chemical Society. Mendeleyev’s Periodic Law opened a new era in the history of chemistry.

Mendeleyev was interested in many branches of science, indeed there is hardly any field of science that was not enriched by his contribution. His numerous works dealt with many subjects: properties of liquids, theories of solutions, the development of the gas law, the use of oil and many others.

D. I. Mendeleyev was a great patriot. He did everything for the development and progress of his country.

D. I. Mendeleyev continued his research work to the very last day of his life. He died in 1907.

The world is thankful to Mendeleyev for his great contribution to the world science. At present there is hardly anyone who doesn’t know this Russian scientist and his Periodic Law. We are proud of D. I. Mendeleyev who did so much for his country, for the development of world science.

Ex. 30. Answer the following questions.

1. When was D. I. Mendeleyev born? 2. Where was he born? 3. When did he go to gymnasium? 4. What subjects did he like? 5. What Institute did he enter? 6. Where did he work after the graduation from the Institute? 7. When was he granted the Doctor of Science degree? 8. What was he granted this degree for? 9. What was Mendeleyev’s greatest discovery? 10. What did he present to the Russian Chemical Society? 11. What other problems was Mendeleyev interested in? 12. What subjects did his numerous works deal with? 13. When did he die?

Ex. 31. Retell the text according to the following plan:

1. D. I. Mendeleyev's childhood.

2. The gymnasium and the Pedagogical Institute.

3. D. I. Mendeieyev's work at the Technological Insti­tute and at the University.,

4. His research work.

5. D. I. Mendeleyev's greatest discovery.

6. D. I. Mendeleyev's greatest contribution to science.

7. D. I. Mendeleyev is a great chemist and patriot.

Ex. 32. Insert this, that, these, those or it and translate the sentences:

1. ... terms are no longer associated with the origin of the substances. 2. ... phenomenon is not unknown in organic chemistry. 3. If ... two gases are mixed at high tem­peratures, a great amount of ... chemical substance is produced. 4. ... substance is far from ordinary and possesses a lot of highly interesting properties. 5. M. V. Lomonosov made brilliant discoveries at ... time. 6. Since ... time science and 'technology have made a great progress.

Ex. 33. Substitute that or these for the repeated noun:

1. Natural rubber is of higher quality than rubber produced artificially, 2. The chemists noticed the differences between substances derived from living matter and substances derived from materials. 3. Among the organic compounds the compounds containing only hydrogen and carbon, the so-called hydrocarbons, are the least reactive. 4. Physical changes are the changes which affect the state or condition of matter without changing its composition. 5. At temperatures higher than the temperatures mentioned before most substances melt or evaporate.

Study the following grammar rule.

Imperative Mood
We use the verb to let when dealing with I/ we/ he/ she/ it/ they Use Possessive pronouns me/ us/ him/ her/ it/ them	We use the Infinitive form without the particle ‘to’ dealing with you
Let me do it. Let him answer that question. Let it rain! Let them come in.	Do these exercises for the next lesson. Don’t go out alone. Give me your note-book. Don’t ask stupid question.

Ex. 34. Translate the following instructions.