2018-02-13
975
Complete the following sentences using the words from the list below. Some of the words can be used more than once.
Level, layer, blanket, top, evidence, to mention, to lead, to contaminate, to isolate, nitrogen, oxygen, argon, spontaneously, gradually, to escape, atmosphere, density, bottom.
1. … for other gases in the … came towards the end of the 19th century.
2. The work … to the discovery was an investigation into the … of ….
3. The … lying all over the Earth like a … is called the ….
4. So far we’ve … …, …, carbon dioxide and water vapour.
5. By the time you get to 50 miles above the sea …, there’s practically no air left.
6. The main gas that … the atmospheric … is ….
7. Gases mix together ….
8. So a gas that … from the Earth becomes a part of the ….
9. … more and more … is added to the ….
10. … and … were … long before the end of the 19th century.
11. We live at the … of a very deep “ocean of air”.
12. There’s enough air to breathe at the … of Mt. Everest.
5. Translate the following sentences into English:
1. Хімія – це наука, яка вивчає властивості, якості та будову матерії.
2. Хімія вивчає різноманітні форми матерії, а фізика має справу головним чином з природними перетвореннями й дією різних форм енергії.
3. З хімічної точки зору дощова та грунтова вода насправді не є чистими.
4. Гази не мають ні власної форми, ні об’єму.
5. Вода – це складна речовина.
6. Більшість речовин є складними за будовою та можуть ділитися, утворюючи простіші речовини.
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7. Якщо речовину не можна розкласти або отримати сполученням простіших речовин, її називають елементом.
8. я знав, що ми проводитимемо дослід.
9. Він вважав, що рідина випарується швидше.
10. Будь-який елемент у поєднанні з киснем утворює оксид.
11. Кисень може перетворюватися на рідину, яка кипить при температурі – 183° С.
12. Оскільки водень – найменший із елементів, його щільність є найменшою з усіх речовин.
13. Після закінчення досліду отримали водень.
14. Ми почали розрахунки після того, як дослідження були завершені.
15. Молекули – це найдрібніші частки, що утворюють усі види речовини.
TEXT 12
ORGANIC CHEMISTRY
Learn the new vocabulary:
| can’t help (doing smth) | не могти (не робити щось) |
| to obtain | добувати, набувати |
| living thing | живий організм |
| ordinary | звичний, звичайний |
| to convert | перетворювати |
| exception | виняток |
| man-made | штучний |
| manufacturing | виробництво |
| petroleum | нафта |
| marine | морський |
| separate | окремий |
| since | тут: оскільки |
1. Read and translate the text:
Non-chemist can't help being surprised to learn that many chemical compounds are obtained from living things. For example, sugars, ethanol, methane, urea, etc.
What all these compounds have in common are the elements carbon and hydrogen. Thus, it can be said that nearly all compounds obtained from living things are carbon compounds.
In the early days of chemistry no one ever thought of obtaining compounds from living things in the laboratory. The idea was that there were special processes going on inside the organism (living thing). The special processes were believed to be essential for the formation of the compounds. So, chemists considered the compounds from organisms to be somehow special and different from "ordinary" chemicals that could be made in the laboratory. They called chemicals from living things organic chemicalsand the others inorganic chemicals.
However, in 1828 a chemist called Wohler showed organic chemicals to be just ordinary chemical substances. He did this by converting an inorganic chemical into an organic one simply by heating it in the laboratory. Gradually, more and more organic chemicals were shown to be just like ordinary chemicals. But we still use the terms "organic" and "inorganic" to divide chemicals into two classes. Nowadays, however, we use the term "organic compounds" to mean carbon compounds,there being some exceptions to the rule.
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Most of the organic chemicals we have nowadays are man-made and are obtained directly from organisms. However, the main raw material for manufacturing organic chemicals is petroleum, it having been formed in the past from marine organisms.
Why do we have to separate a branch of chemistry just for carbon compounds? Couldn't its compounds be included with those of other elements?
There's a simple reason for keeping carbon compounds separate: there are just too many of them. There are more compounds of carbon than compounds of all the other elements put together. Organic chemistry is therefore to be a very large branch of chemistry. It includes millions of compounds. Most of these are compounds of carbon involving just a few other nonmetallic elements, for example, hydrogen, nitrogen, oxygen and the halogens.
Why does carbon have so many more compounds than other elements? What is special about it? The answer to these questions is: carbon atoms have the special property of being able to join together to form chains of atoms. The chains may be short, or they may be hundreds or even thousands of atoms long.
Since the carbon chain can be practically of any length, the number of possible hydrocarbons is enormous.
2. Find in the text sentences stating that:
1. The material for producing organic chemicals used to be found in the sea.
2. In the past chemists didn't even think of preparing organic chemicals in the laboratory.
3. The reason for a great variety of carbon compounds is its ability of forming atom chains of different length.
4. The method of obtaining an organic chemical from an inorganic one turned out to be very simple.
5. There were some experiments proving that man-made organic compounds didn't differ much from ordinary chemicals.
