in, o f with, on, by
1.
All the halogens consist ... diatomic molecules. 2. The most
common ... the halogens is chlorine. 3. Chlorine was first made ... the
action... manganese dioxide... hydrochloric acid. 4. It was obtained by
K.W. Schccic... 1774. 5. Now chlorinc is manufactured... a large scale
... the electrolysis ... a strong solution ... sodium chloride. 6. Bromine
occurs... the form o f compounds... small quantities. 7. Bromine has an
irritating effect ... the eyes and throat. 8. Iodine is an almost black
crystalline solid ... a slightly metallic lustre. 9. The I2 molecules ... the
solutions ... chloroform, carbon tetrachloridc and carbon disulphide
closcly resemble the gas molcculcs. 10. The solution iodine ... alcohol
is brow n... colour.
Ex. 9. a) Check up if you remember the following:
much
гораздо
,
сравнительная степень
fa r
намного
agreatdetd
*
л р и ш т ш к »
-»
1тчшпаьт
я Ш
т и м р п и
much darker, far less abundant, still harder, a great deal more, much
lighter, much more beautiful, far less activc
b) Translate the sentences into Russian.
1.
The first solution of sodium chloride is much stronger than the
second solution. 2. Fluorine is a great deal more activc than the other
halogens. 3. Iodine is much heavier than bromine. 4. A surfacc coating
protects some compounds from still further oxidation. 5. Potassium is
much lighter than rubidium, and sodium is still lighter. 6. Amorphous
boron is much more reactive chemically than is the harder, more expensive
crystalline variety. 7. The nuclcus o f an atom is much smaller than is the
atom itself. 8. Antimony is much more metallic in appcarancc and in
properties than either phosphorus or arsenic. 9. Studies o f crystal chem
istry have attracted much greater interest during the last decade than
ever before. 10. Carbon tetrachloride is a liquid much more dense than
water. 11. Bromine is far less abundant than chlorinc or fluorine. 12. Steel
is far less brittle than cast iron.
66
1. The text that you must have read describes the properties of halogens.
2. This student can’t have started the reaction before learning the properties
of the substanccs. 3. The author may have supposed that this description
would help to understand his idea better. 4. The teacher may have spoken
about such reactions, I don’t remember. 5. Mendeleyev could have presented
his periodic system himself, but he was ill. 6. You ought to have been more
attentive working in the laboratory. 7. The scientists of our faculty may have
discovered some new properties of electrodes, now they arc writing an article
on this problem. 8. Everyone must have noticcd a blue-violet vapour when
iodine was being warmed. 9. The reaction may not proceed to completion
without heating. 10. The laboratory assistant can’t have done all the work
alone. 11. Our friends haven’t come yet, they must be still working in their
laboratory. 12. You should have paid more attention to a theoretical course
before starting your practice. 13. The reaction must have occurred, the colour
ofthe reagents has changed. 14. Chemistry couldn't have reached the present
level of development without the atomic theory. IS. The discovery of the
periodic law must have been the greatest discovery in the nineteenth-century
chemistry. 16. The researchers would have tested their results by experiment,
but they had no all the necessary apparatus. 17. Newton may have thought
that light was a stream of particles. 18. Suggestions were made as to what
may have occurred during the reaction.
Ex. 11. Translate the sentences into English.
1. Галогены— это элементы VII группы. 2. Все галогены состоят
из двухатомных молекул. 3. Самый обычный из галогенов, хлор, —
это зеленовато-желтый газ. 4. Хлор был впервые получен шведским
химиком Шееле в 1774 году. 5. Сейчас хлор получают в больших мас
штабах электролизом раствора хлорида натрия, б. Бром встречается
в малых количествах в виде соединений в морской лоде и природных
отложениях солей. 9. Йод также может встречаться в очень малых
количествах в морской воде.
Ex. 12. Make up questions to the italicized parts of the sentences.
1. Halogens may have interested chemists since early times (3).
2. Iodine is an almost black crystalline solid with a slightly metallic lustre
(3). 3. The solutions of iodine in water containing potassium iodide and in
alcohol are brown (3).
Ex. 13. Answer the following questions:
1. What elements arc called halogens? 2. Why may the halogens
have interested chemists? 3. What is the most common of the halogens?
4. When was chlorinc obtained? 5. In what way is chlorinc obtained
now? 6. What kind of element is bromine? 7. Where docs bromine occur
and in what form? 8. In what way is iodine made commercially? 9. What
kind of element is iodine?
Ex. lO.TYanslntc the sentences into Russian, paying attention to modal verbs.
67
|