extraction. 3. The symbols ... these elements were derived ... their Latin
names. 4. There arc elements which can ex ist... two different forms ...
the same physical state. 5. Reactions... ozone arc completely different...
those ... oxygen. 6. White phosphorus catches fire ... air ... room
temperature. 7. The atom s... all common gaseous elements exist... pairs
... the inert gases.
Ex. 9. Supply the definite or indefinite article.
1.
Mendeleyev is ... famous Russian chemist. 2. Mendeleyev is ...
founder of the Periodic Law. 3. Professor N i s ... author o f a great number
o f papers and books. 4. Swedish chcmist Berzelius w as... great discoverer.
5. Do you know who ... discovcrer of the atomic theoiy was? 6. Niels
Bohr was ... Danish physicist. 7. Chemistry is ... branch o f knowledge.
8. Section II is concerned with ... nature of radioactivity. 9. Dr. N dis
covered ... new law. 10. Faraday was ... well-known English physicist.
Ex. 10. Translate the sentences into Russian, paying attention to the
predicates.
1.
Chemistry concerns the compositions o f m atter and their
transformations. 2. A great number of Russian scientists, among them
Mendeleyev, Lomonosov, Butlerov ct al., could be mentioned as
contributors to the world science. 3. There arc several fields o f chcmistry
in which Russian scientists have achieved significant progress. 4. The
Periodic Law laid the foundation for the modem development of chcmistry.
5. In the molten state metals are able to interact with one another. 6. Alloys
which contain only two metals arc referred to as bimetallic. 7. Science has
become an important part of the modem world. 8. Chemists are needed
almost in every field of life. 9. The theories and laws
of chemistry are no
less exact as those of physics. 10. Silicon, the fourteenth element in the
periodic table might be called a congener o f carbon, in Group IV.
11. Attempts to arrange the elements in a definite order were followed by
a great discovery, the discovery of the Periodic Law. 12. The periodic
tabic may be interpreted in terms o f electronic structure o f atoms.
.13. Radioactivity was discovered by Henry Becqucrcl in 1896. 14. The
change o f the program of experimentation could have given more accurate
results. IS. Before definite chemical evidence for the compound nature of
a substance was obtained, the substancc had been considered an clement.
16. In 1903 scientists recognized that radioactivity involves the spontaneous
transmutation of elements. 17. Here wc arc going to give a detailed account
of this phenomenon. 18. Heating was to have an important influence on
the rate of the reaction. 19. Two points should have been determined: the
composition of the sample and the relative weights of its constituent parts.
20. The result o f the comparison may be completely the opposite. 21. The
next step was to arrange the data in a table. 22. At any given temperature
a molecule of a light gas such as helium or hydrogen will have the same
average kinetic energy. 23. Chemists must have
known a great number of
reactions that can procccd without catalysts. 24. Few chcmical reactions
involve just a single elementary proccss. 25. Wc have prevented the
formation of by-products. 26. New methods of investigation arc being
developed, they are much more effective than the older ones.
Ex. 11. Translate the sentcnccs into English.
1. В 1818 году Бсрцслмус опубликовал список «атомных вссов».
2. Берцелиус ввел современные символы для химических элементов.
3. Некоторые элементы могут существовать в двух различных формах
в одном и том же физическом состоянии. 4. И озон, и молекулярный
кислород содержат только атомы кислорода. 5. Реакции озона совер
шенно отличны от реакций кислорода. 6. У озона— три атома кисло
рода, а у молекулярного кислорода— два. 7. Чтобы избежать путани
цы, молекулы газа записываются как
0 2, N2 и т. д. 8. Красный фосфор
стабилен на воздухе при температуре 240°С. 9. Белый фосфор, напри
мер, воспламеняется на воздухе при комнатной температуре.
Ex. 12. Make up questions to the italicized parts of the sentences.
1.
The symbols began as
a simple shorthand for referring to
the names
of the elements (3). 2. Ozone will
immediately oxidize metallic
silver (3).
3. There is no way of discovering
how many atoms arc combined together
in
any solid (2).
Ex. 13. Answer the following questions:
1.
What were the symbols introduced for? 2. Who introduced the
symbols for chcmical elements and when did he do it? 3. What significance
did symbols acquire? 4. What is the difference in writing allotropic
modifications o f elements?
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