2. Прочитайте текст за допомогою словника та дайте відповіді на наступні запитання:

1. Where did Mendeleyev start ordering the elements?

a) at school;

b) at St. Petersburg University;

c) abroad.

2. Why did Mendeleyev turn to ordering the elements? Because:

a) other scientists' attempts failed;

b) he had talent;

c) he didn't like disorder.

3. What did the researchers try to do to find some order of the elements?

a) they compared different properties;

b) they read scientific literature;

c) they denied the earlier attempts of the scientists.

4. How did Mendeleyev list the elements?

a) according to their names;

b) according to their atomic weights;

c) according to their chemical symbols.

5. What did scientists of Mendeleyev's time think about atoms of different elements?

a) they were independent particles of nature;

b) they were closely connected;

c) they belonged to a well-ordered system.

3. Знайдіть українські еквіваленти наступним словам, словосполукам та термінам з тексту с:

1. research worker 10. to exercise 18. applied

2. well-ordered 11. to influence 19. increasing

3. majority 12. could not bear 20. insight

4. firmly 13. had been appointed 21. for example

5. were convinced 22. weight

6. particles 14. disorder 23. tools

7. advanced 15. comparison 24. nucleus

8. realized 16. according to 25. lucidly

9. unsuccessful 17. similarity 26. density

4. Поєднайте синоніми з вправи 3 та вправи 4:

a) to affect i) for instance r) properly organized

b) investigator j) centre s) in agreement with

c) were sure k) very small bits t) thickness

d) unlucky 1) understood u) used

e) resolutely m) to exert v) disliked very much

f) progressive n) chaos w) intuitive cognition

g) had been given o) likeness x) heaviness

a position p) making greater y) clearly

h) instruments q) collation z) a greater number

TEXT D

Уважно прочитайте наступний текст та доберіть назву, що найбільш підходе:

1. History of Scientific Discoveries.

2. Mendeleyev's Contribution to Chemistry.

3. Elements of the Periodic Table.

4. The Periodic System of Elements.

In spite of the importance of the contributions that had been made earlier, the greatest portion of credit for the development of the Periodic System must undoubtedly go to the Russian scientist, D. I. Mendeleyev. The understanding that the properties of the elements can be represented as periodic functions of their atomic weights made possible classification that has suffered few significant changes in the subsequent years. In March of 1869 D. I. Mendeleyev published his first description of the Periodic System in which he gave the arrangement of the elements in terms of their increasing atomic weights. He fully realized the importance of this periodicity. In his first article D. I. Mendeleyev pointed out the similarities of a number of properties of certain elements and changed the order of atomic weights where necessary in order to have the group similarity. D. I. Mendeleyev left vacant positions in his table for yet undiscovered elements and expressed the opinion that the chemical and physical properties of the elements would be discovered, as he predicted, from their positions in the table. In the summer of 1871 D. I. Mendeleyev published a more comprehensive work and called it the Periodic Law. At this time he presented the more familiar form of the Periodic Table and although it differs somewhat from the one we use today, it is in general the same. In his publication of 1871 D. I. Mendeleyev used the periodic character to predict the properties of the elements which would be later described as those of scandium, gallium, and germanium. The remarkable agreement of the properties of these elements as they had been described by Mendeleyev and those that were observed later is without doubt a complete justification of D. I. Mendeleyev's faith in his Periodic Law. In December 1945 Glenn Seaberg made his first publication of a Periodic Table which described a new actinide series beginning with actinium. He said that American scientists were proud and happy to honour the name of D. I. Mendeleyev by calling element 101 "mendelevium".

TEXT STUDY