Химия EXERCISES просмотров - 207
Answer the questions
1. When are the molecules able to break out of the lattice?
2. When does the substance lose its definite shape?
3. Why do liquids give off smell?
4. What happens when a liquid is heated?
5. What is evaporation?
6. What is condensation?
2. Give synonyms:
essential, universal, to cause, liquid, to deposit, fluid, to make, general, principal, to
3. Give antonyms:
to cool, eventually, to supply, to attract, boiling point, to repell, to provide, at last, to
heat, freezing point
4. Translate the following sentences:
1. Molecules are in constant motion, the motion becoming more rapid with the increase of temperature. 2. The temperature being raised, the kinetic energy is increased. 3. The evaporation increases with the temperature, other conditions being equal. 4. Water power being one of the best and cheapest ways of producing electricity, it is widely utilized to drive generators which provide electric current. 5. This material being used in electronics, its properties should be studied closely. 6. Non-metallic materials are of great importance, some of them being widely used in place of metals. 7. They have to compare their experiments, their results being different. 8. The data having been obtained, we discussed the results at the conference. 9. Water being heated, it boils at 100°C. 10. The molecules of the solid when heated break out of the lattice, the solid melting. 11. Gaining enough energy to move far apart, the molecules often collide with the sides of the container they are in. 12. The students investigating this phenomenon carry out the experiments in the laboratory of general chemistry. 13. Breaking out of the lattice the molecules of the solid gain enough energy, being free to move. 14. The experiment being carried out by the researcher deals with the liquid state of matter. 15. Having prepared everything for the experiment, they reviewed once more the theoretical back- ground for its fulfillment.
Water plays the most essential part in our lives. It is universally needed, but it is not naturally present everywhere. Where does water come from? We know that the evaporation of water from rivers and from the sea causes the water vapour to be held in the atmosphere, from which, on cooling, it is deposited as rain. This rain eventually finds its way back to the rivers and sea and so the cycle begins all over again. The heat of the sun supplies the energy for the evaporation.
Rain-water is not chemically pure, although it is the nearest approach to a pure water among natural waters. Containing little or no mineral matter, it does contain dissolved gases. Water was originally thought to be an element; it was produced by both Priestley and Cavendish by passing a spark through a mixture of hydrogen and oxygen in the proportions of two volumes to one; Lavoisier showed water to be a compound. Water itself may be prepared in the laboratory by burning hydrogen in oxygen or in air, or by passing an electric spark through a mixture of oxygen and hydrogen: 2H2 + 02 = 2H20.
1. Find Ukrainian equivalents:
1. essential part а. хімічно чистий
2. all over again b. мінеральна речовина
3. chemically pure c. електрична іскра
4. mineral substance d. все спочатку
5. an electric spark e. суттєва роль
2. Find English equivalents:
1. безколірна рідина а. dissolved gases
2. пропускати іскру b. to pass a spark
3. чиста вода c. mobile liquid
4. рухома рідина d. pure water
5. розчинні гази e. colourless liquid
1. Complete the sentences with the verb in the correct form: Present Simple, Future Simple Tenses. Watch tadpoles grow 16) If you look in a pond, you ..... (see) in a shallow water great lumps of jelly. That ..... (be) frog's spawn. Mother frog ..... (lay) up to 800 eggs. Don't think she ..... ( take) care of them. She ...... ( leave) them, floating on the surface to look after themselves as soon as the eggs are laid. Then in a few days if you look at an egg you ..... ( notice) a black spot,... [читать подробенее]
1. Put in a\an or the where necessary. ..…Britain, in which ... fifty million people live and work, is,.. land of... great variety. There are many large cities, but they are surrounded with ... quiet countryside. There are ... plains in ... east, hills in... center and south-west, and ... mountains in ... north. Some parts of ... country are almost without ... trees while others have ... great forests, ... south is ... land of... rivers, but Scotland is... land of ... lakes. One of ...... [читать подробенее]
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She was sent to the neighbouring republic of Uzbekistan to continue her education. There, in Tashkent, under a decree signed by Lenin, the first state university in Central Asia had been opened in 1920. Tajibayeva joined its geological department. She was in Tashkent when the Great Patriotic War of 1941-1945 broke out. She attended lectures in the morning and nursed the wounded in the hospitals at night. In 1943 Patchaim Tajibayeva graduated from the University with honours. She was thinking... [читать подробенее]
UNIT FIFTEEN THE SOVIET UNION TODAY Topics and Texts for Discussion* V. I. Lenin, the founder of the first socialist state. The Great October Socialist Revolution, a turning point in the history of mankind. The USSR, a voluntary union of free nations. The new Constitution of the USSR. Fundamental human rights guaranteed to Soviet citizens. The Soviet socialist way of life. Large-scale construction in the USSR. Contribution of Komsomol members to the economic development of the country. The... [читать подробенее]
Text 1. From the history of Belarus Additional texts for reading Exercises 1. Replace the following definitions by one word from text 3: – land along each side of a river or canal; – things, circumstances, surroundings, that make life easy or pleasant; – a part of a town or a country marked out for a special purpose; – to be shut in on all sides; – buildings and equipment of an institution, factory; – buildings where goods are made (esp. by... [читать подробенее]