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  1. Личные - это дополнительные трудовые гарантии лицам, избранным в профсоюзы тем, кто непосредственно сталкивается с работодателем и т.д.
  2. Участие в международных объединениях, с какими странами кооперируется, союзы.

(Prepositions, conjunctions)


1. Переведите на русский язык, обращая внимание на значение предлогов; помните, что помимо прочих значений они передают значения падежей: of - родительного, to -дательного, with, by - творительного.

of: 1) the pressure of water; 2) to speak of something; 3) a page of the book; 4) Many pupils of our schools think of space travels; 5) One of the boys makes a model of a rocket of paper and wood with the help of his teacher; 6) The capital of Great Britain is London; 7) made of steel.


to: 1) to give documents to the assistant; 2) to send to Moscow; 3) to show to the students; 4) to go to the factory; 5) to come to the lake; 6) the way to the station; 7) to reduce to the minimum; 8) At the lesson pupils listen to the teacher, give answers to the teacher in English, and put question to each other.


with: 1) to illustrate with tables; 2) to write with a pencil; 3) a glass with water; 4) to speak with our friends; 5) to work with an instrument; 6) to connect the centre with the airport; 7) to open with a knife.


by: 1) to read books by Tolstoy; 2) The model was made by the students; 3) to sit by the window; 4) The door was opened by the secretary; 5) to finish the work by 5 o’clock; 6) He will come back by the end of the week; 7) to call by analogy.


2. Переведите на русский язык, обратите внимание на многозначность предлогов и сравните их употребление в английском и русском языках.

from: 1) to stretch from the South Pole; 2) to last from December to January; 3) to be free from ice; 4) to analyze water from the sea; 5) to be hot from be sun; 6) to return from the Arctic expedition; 7) Bring me some flowers from the field and from the garden; 8) The road from the river runs through the forest; 9) from 5 o’clock till the evening; 10) to translate from English.


in: 1) in Europe; 2) In cities people live in high buildings; 3) It was in April in 1961; 4) in winter; 5) in two days; 6) He will return in a year; 7) in less than two hours; 8) two days in advance; 9) to differ in strength and hardness; 10) to be rich in gold and minerals; 11) to be large in area.


at: 1) People work at different places; 2) He works at a power station; 3) We study at the institute; 4) He stands at the blackboard; 5) We sit at tables; 6) at a lower price; 7) Lessons begin at 9 o’clock; 8) at five minutes to eleven.


into: 1) to translate into English; 2) to transform into another form; 3) to make into a ball; 4) I put the key into my pocket; 5) Come into the room.


out of: 1) I took the key out of my pocket; 2) He came out of the room; 3) to fall out of the window; 5) to thrust out of the box.


for: 1) the book for you; 2) to last for two days; 3) for two centuries; 4) for a year; 5) for half an hour; 5) for a week.


3. Переведите, употребив нужный предлог.

to make a report (at, on) the meeting; to go (on, to) the station; to have dinner (on, in) the kitchen; to make a model (of, from) paper; to come (from, out of) Moscow; to return (to, by) 5 o’ clock; to begin work (in, at) 9 o’clock; to teach (in, at) school; to happen (in, on) spring; to take (out of, from) a box; lessons begin (in, on) September; to work (for, at) five hours.


4. Заполните пропуски словами, которых требует данный предлог.

1. Can you finish the work by ...? (this month, tomorrow, 5 hours) 2. I shall be at home for ... . (2 hours, 3 o’clock, Monday) 3. The expedition will return on ... . (August, Monday, winter) 4. Work begins at ... (the morning, 9.30, this week) 5. I came back in... . (9 o’clock, 2009, Sunday) 6. October comes after ... . (November, September).


5. Заполните существительное в притяжательном падеже существительным с предлогов. Не забывайте об определённом артикле.

Образец: My friend’s book. — The book of my friend.


1. These students’ work. 2. I like to work in my father’s room. 3. Tell me Peter’s address. 4. What is this man’s profession? 5. My dog’s name is Toby. 6. Ivanov is our family’s friend. 7. Animals’ food differs from people’s food. 8. Export and import are important factors in the country’s economy. 9. Many young people want to choose the teacher’s profession. 10. In the morning we see the Sun’s disk in the East. 11. The engineers’ work is important for our country’s technical progress.


6. Заполните пропуски соответствующими предлогами.

1. I study ... the Medical Institute. 2. Once a year I go … my old school. 3. I meet my school friends ... the meeting. 4. Some … them work ... mills, some serve ... the army, many study … institutes. 5. We speak ... the tenth-formers ... our life and work. 6. Our director gets many letters ... his old pupils. 7. He reads some ... the letters. 8. We listen ... him … great interest. 9. We come home late … the evening. 10. We come ... the Institutes ... 9 ... the morning. 11. Thousands of students graduate ... institutes and universities every year. 12. Some ... them work … various branches ... industry, while others carry out research. 13. Evening department students get every assistance necessary ... their studies ... the state. 14. Many people combine work ... studies. 15. Studies begin … the lst ... September. 16. Our country is rich ... coal, oil and iron ores. 17. There is a great deal ... snow ... the North … our country ... winter. 18. ... general this part ... the country can be called agricultural one. 19. The highest mountains in Britain are ... the North-West. 20. ... the 19th century Great Britain became the most advanced industrial country ... the world.


7. Вставьте подходящие по смыслу предлоги, переведите текст.

We are students. ... the morning we go ... the institute. Our lectures begin ...9 o’clock. We have no lectures … Sunday. We take examinations … January and June. We do not study … summer. We come … the classroom and sit down … the tables. We take our books and notebooks … the bags and put them … the tables. Our pens are … the table too. Our bags are usually… the tables. Sometimes they are … the table ... the floor. During the lesson we go … the blackboard and write sentences … it. When the lessons are over we go … … the c1assroom and go …. home. We usually come back … the institute … 3 o’clock … the afternoon. ... home we have dinner and ... dinner we have a short rest ... an hour or two. Then we prepare our lessons ... the next day. Usually ... three or four hours we finish our work and may watch TV or go ... our friends.


8. Переведите предложения, учитывая, что русскому предлогу “с” в

английских предложниях соответствуют предлоги “with”

“from”, ”since”.

а) 1. We have made friends with George since he returned from the North. 2. Please don't take the book from the shelf: since yesterday I have begun reading it together with Peter. 3. The students have studied English since last year; now they

can speak English with their teacher and read technical literature with the help of a dictionary.

б) 1) работать с прошлого года; 2) играть с детьми; 3) взять со стола; 4) говорить со студентами; 5) стать инженером с 1989 года; 6) снять со стены (take down).

в) 1. Дети любят книги с картинками. 2. С верхнего этажа нашего дома мы видим весь город с его широкими улицами и новыми зданиями 3. С тех пор как умер его отец он живет с братом. 4. Принесите мне с почты конверт с маркой. 5. Я не видел его с прошлого воскресения. 6. С будущего месяца мы будем работать с инженером, который приехал с Дальнего Востока.


9. Переведите следующие группы слов и предложении на английский


I) квартира нашего преподавателя; 2) исследовательская работа молодых инженеров; 3) фамилии этих студентов; 4) ответ докладчика; 5) Отец этого студента – химик. 6) Кабинет декана большой и светлый. 7) Как зовут вашего старосту? 8) работать в лаборатории; 9) идти в лабораторию; 10) использовать в сельском хозяйстве; II) делать инструменты из стали; 12) приезжать из деревни; 13) снять со стола; 14) разговаривать с инженером; 15) делать из дерева; 16) говорить о людях; 17) использовать для работы; 18) читать книги Пушкина; 19) в нашей стране; 20) выпуск­ники нашего института; 21) среди бывших выпускников; 22) учиться в институте; 23) присутствовать на лекции; 24) снабжать оборудо­ванием; 25) идти в институт; 26) студенты нашего института; 27) писать карандашом; 28) строить из стали и стекла; 29) послать телеграмму главному инженеру; 30) информировать о новом спутнике; 31) написать письмо приятелю; 32) фамилия нашего преподавателя; 33) думать об институте; 34) производить из пластиков.




Переведите текст, обращая внимание на предлоги. Выпишите из текста словосочетания, в которых существительное является опре­делителем другого существительного. Перескажите текст.




The continent of Antarctica liеs at and around the South Pole within the Antarctic circle. It is in the centre of the Earth's southern part on the opposite side of the globe from the areas where most of the population of our planet lives.

Antarctica stretches from the South Pole to the 70th lati­tude and is twice as large in area as Australia.

Twenty million square kilometers of the land mass is thick ice which forms the largest load on the earth's crust; in some places it depresses the continent below sea level. The stormy ocean isolates Antarctica from other lands. In winter the tem­perature is coldest on earth, sea water freezes and doubles the area of the continent: it brings its border to the 50th parallel - the latitude of Paris. The summer season lasts for two months - from December to January. When the daily hours of sunshine are longest air temperature rises to 2 or 3 degrees Centigrade above zero. On a clear summer day the icebergs change color from red to violet and the sea is green but all the rest is white, quite white. A small piece of land free from ice and snow with a lake in its centre lies about 250 miles from the Mirny. The water in the lake is icy cold but the stones around it are quite hot from the sun rays. Because the ice reflects most of the solar heat back into space, ice and snow do not melt, but any object may get hot in the sunshine.

Geological exploration shows that the continent in the not too distant past had a rich flora and fauna. Geologists find signs of plants and animals that are characteristic of a temperate climate which brings Antarctica to the centre of interest in many fields of science. Geological exploration may help to solve many questions about the history of the earth. What lies under the cover of ice? How long did the life exist here? How many thousands of centuries ago did forests grow here and huge animals people them? Why did they disappear? The unique geography of the Antarc­tic makes it a great natural observatory for the study of the earth and its three southern poles: the geographic, magnetic and geomagnetic. Antarctica may become a laboratory for the scientists of many nations where they can work together and develop inter­national cooperation and contacts.



10. Переведите предложения, обращая внимание на составные пред­логи: according to - в соответствие, согласно; as far as - насколько; because of - из-за; by means of - посредством; due to - благодаря, вследствие, из-за; in addition to - в дополнение, плюс к; in front of - перед; in order to - для того, чтобы; in spite of - несмотря на; instead of - вместо; on account of -вследствие, из-за; owing to - благодаря, из-за, вследствие; thanks to - благодаря, из-за.

1. By means of this device we can now carry out more opera­tions in shorter time. 2. The work goes on according to schedule. 3. The engine didn't operate well because of bad fuel. 4. In order to protect the surface from heat and cold it was covered with special substance. 5. Due to this new trolley-bus route the passenger service in the city was improved. 6. The monument was restored in spite of many difficulties. 7. Who can repair the apparatus instead of him? 8. No planes took off on that day on account of low clouds. 9. Is there any high building in front of your house? 10. Owing to his works not only was the problem solved at last but a wholly new approach to it was introduced. 11. The expedition sailed as far as Borneo. 12. In addition to sails the boat was also supplied with a motor. 13. In addition to the usual methods of computation they made use of computers. 14. According to the information the ship will arrive on the 10th of April. 15. I go by bus as far as the library and then walk a few blocks to my office. 16. They didn't go to the country because of the rain. 17. In big ports ships are loaded and un-loaded by means of cranes. 18. The train did not arrive in time due to the snow storm. 19. Who is sitting in front of you? 20. The new equipment was used in order to test the vibration of the engine. 21. He left in spite of all my protests. 22. What book can you give me instead of that one? 23. The match was de­layed on account of heavy rain. 24. Owing to the new system of regulations the number of accidents went down. 25. Thanks to his help we finished our work early.


11. Переведите предложения, обращая внимание на значение слова “which”.

1. The Moon has no atmosphere which is necessary for the life of plants. There is no atmosphere on the Moon, which is the reason of its being lifeless. 2. Plastics are a new material which is produced of chemicals. Plastics can be moulded under heat and pressure, which makes them important in industry. 3. Glass has some properties which have been recently discovered. Glass can be subjected to different methods of treatment, which should be taken into consideration by the engineer.


12. Переведите предложения, обращая внимание на составные союзы: both ... and - как ... так и; either ... or - или ... или neither ... nor- ни ... ни, sо that - так, чтобы, с тем чтобы.

1. Both the bridge and the tunnel will be finished in time. 2. I shall leave either tonight or tomorrow. 3. I could find him neither at home nor in the office. 4. They crossed the mountains sо that they could reach the village before dark. 5. You can get to this part of the city either by bus or by the underground. 6. Our firm knows neither crisis nor unemployment. 7. The sun gives us both light and heat.




100 наиболее употребляемых неправильных глаголов в английском языке

№ Глагол 2 форма 3 форма Перевод

1 say said said говорить

2 make made made делать

3 go went gone идти

4 take took taken брать

5 come came come приходить

6 see saw seen видеть

7 know knew known знать

8 get got got получать

9 give gave given давать

10 find found found находить

11 think thought thought думать

12 tell told told сказать

13 become became become становиться

14 show showed shown показывать

15 leave left left оставлять

16 feel felt felt чувствовать

17 put put put класть

18 bring brought brought приносить

19 begin began began начинать

20 keep kept kept держать

21 hold held held держать

22 write wrote written писать

23 stand stood stood стоять

24 hear heard heard слышать

25 let let let позволять

26 mean meant meant иметь в виду, намереваться

27 set set set ставить, устанавливать

28 meet met met встречать

29 run ran run бежать

30 pay paid paid платить

31 sit sat sat сидеть

32 speak spoke spoken говорить

33 lie lay lain лежать

34 lead led led вести

35 read read read читать

36 grow grew grown расти

37 loose lost lost терять

38 fall fell fallen падать

39 send sent sent отправлять

40 build built built строить

41 understand understood understood понимать

42 draw drew drawn рисовать

43 break broke broken ломать

44 spend spent spent тратить

45 cut cut cut резать

46 rise rose risen подниматься

47 drive drove driven вести машину

48 buy bought bought покупать

49 wear wore worn носить (одежду)

50 choose chose chosen выбирать

51 seek sought sought искать

52 throw threw thrown бросать

53 catch caught caught ловить

54 deal dealt dealt иметь дело

55 win won won выигрывать

56 forget forgot forgotten забывать

57 lay laid laid класть

58 sell sold sold продавать

59 fight fought fought драться, бороться

60 bear bore born родиться

61 teach taught taught учить

62 eat ate eaten есть

63 sing sang sung петь

64 strike struck struck ударять, бить

65 hang hung hung вешать

66 shake shook shaken трясти

67 ride rode ridden ездить верхом

68 feed fed fed кормить

69 shoot shot shot стрелять

70 drink drank drunk пить

71 hit hit hit ударять

72 arise arose arisen возникать

73 fly flew flown летать

74 spread spread spread распространяться

75 sleep slept slept спать

76 cost cost cost стоить

77 beat beat beaten бить

78 light lit lit освещать, зажигать

79 bind bound bound вязать, связывать

80 cast cast cast брать, кидать

81 hide hid hidden прятаться

82 swing swung swung качаться, вертеться

83 blow blew blown дуть

84 swim swam swum плавать

85 bend bent bent сгибать

86 wake woke woken просыпаться, будить

87 stick stuck stuck приклеивать, держаться

88 sweep swept swept подметать, мчаться

89 undertake undertook undertaken предпринимать, совершать

90 shut shut shut закрывать

91 steal stole stolen красть

92 tear tore torn рвать

93 hurt hurt hurt повредить, ушибить

94 ring rang rung звонить

95 lend lent lent одалживать

96 sink sank sunk тонуть, погружаться

97 overcome overcame overcome преодолеть, побороть

98 freeze froze frozen замерзать

99 shine shone shone светить, сиять

100 withdraw withdrew withdrawn взять назад






The United Кingdom of Great Britain and Northern Ireland is situated оn the British Isles. The British Isles, lying to the north-west of Europe, consist of two large islands – Great Britain and Ireland and about 5 thousand small islands. Their total area is over 244,000 square kilometres. The UK is one of the world's smaller countries. Its population is over 57 million people. About 80 percent of the population is urban.

The United Kingdom is made uр of four countries: England, Wales, Scotland and Northern Ireland. Their capitals are: London, Cardiff, Edinburgh and Belfast. Great Britain consists of England, Scotland and Wales and does not include Northern Ireland. But in everyday speech Great Britain is used in the meaning of the United Kingdom of Great Britain and Northern Ireland. The capital of the UK is London. The British Isles are separated from the Continent bу the North Sea and the British Channel. The western coast of Great Britain is washed bу the Atlantic Ocean and the Irish Sea.

The surface of the British Isles varies very much. The north of Scotland is mountainous and is called the Highlands. The South, which has beautiful valleys and plains, is called the Lowlands. The north and west of England are mountainous, but the eastern, central and south-eastern parts of England are vast plain. Mountains are not very high. Ben Nevis in Scotland is the highest mountain (1343m.). There are а lot of rivers in Great Britain, but they are not very long. The Severn is the longest river, while the Thames is the deepest and the most important one. The mountains, the Atlantic Ocean and warm waters of the Gulf Stream influence the climate of the British Isles. It is mild the whole year round.

The UK is а highly developed industrial country. It produces and exports machinery, iron and steel products, electronics, chemicals and textile, aircraft and navigation equipment. One of the chief industries of the country is shipbuilding.

The United Кingdom of Great Britain and Northern Ireland is а constitutional monarchy. It means that Great Britain is governed bу the Parliament and the Queen is the Head of the state. The legislative power in the country is exercised bу the Houses of Parliament. The British Parliament consists of two chambers: the House of Lords and the House of Commons. The House of Lords has more than 1000 members (hereditary and life peers and peeresses), although only 250 of them take an active part in the work of the House.The House of Commons is made up of 650 elected members, known as Members of Parliament (МР). It is the real governing body of the UК. The Executive power is exercised bу the Prime Мinister and his Cabinet. The government is usually formed bу the political party which is supported bу the majority in the House of Commons. The Prime Minister is the majority party leader and is appointed bу the Queen. The Prime Minister chooses а team of ministers: twenty of them are in the Cabinet. The second largest party becomes the official opposition with its own leader and the Shadow Cabinet. Two leading parties in Great Britain are the Conservative Party (the Tories, it was formed in 1867) and the Labour Party (formed in 1900). There is по written constitution in Britain, only precedents and traditions.

There are 44 universities in Britain. They аге divided into three types:

1) The old established universities, such as Oxford (founded in 1249), Cambridge and Edinburgh. Oxford and Cambridge together are often called Oxbridge. 2) The 19th – century universities such as London and Manchester. 3) New universities established after World War 2, such as Essay, Lancaster and Vister.




London is the capital of Great Britain, its political, economic and commercial centre. It is one of the largest cities in the world and the largest city in Europe. Its population is about 8 million.

London is one of the oldest and most interesting cities in the world.

Traditionally it is divided into several parts: the City, Westminster, the West End and the East End. They are very different from each other and seem to belong to different towns and epochs.

The heart of London is the City, its financial and business centre. Numerous banks, offices and firms are situated there, including the Bank of England, the Stock Exchange and the Old Bailey. Few people live here, but over a million people come to the City to work. There are some famous ancient buildings within the City. Perhaps the most striking of them is St Paul’s Cathedral, the greatest of English churches. It was built in the 17th century by Sir Christopher Wren. The Tower of London was founded by Julius Caesar and in 1066 rebuilt by William the Conqueror. It was used as a fortress, a royal palace and a prison. Now it is a museum housing The National collection of armour and the Crown Jewels.

Westminster is the historic, the governmental part of London.

Westminster Abbey has more historic associations than any other building in Britain. It dates back to 1049. Nearly all English kings and queens have been crowned here. Many outstanding statesmen, scientists, writers, poets and painters are buried here: Newton, Darwin, Chaucer, Dickens, Tennyson, Kipling, etc.

Across the road from Westminster Abbey is Westminster Palace, or the Houses of Parliament, the seat of the British Parliament. The Clock Tower of the Houses of Parliament is famous for its huge hour bell, built just over a century ago and known as “Big Ben”.

Buckingham Palace is the official residence of the Queen.

The West End is the richest and most beautiful part of London. It is the symbol of wealth and luxury. The best hotels, shops, restaurants, clubs, and theatres are situated there. There are splendid houses and lovely gardens belonging to wealthy people.

Trafalgar Square is the geographical centre of London. It was named in memory of Admiral Nelson’s victory in the battle of Trafalgar in 1805. The tall Nelson’s Column stands in the middle of the square.

On the north side of Trafalgar Square is the National Gallery and the National Portrait Gallery. Not far away is the British Museum – the biggest museum in London. It contains a priceless collection of ancient manuscripts, coins, sculptures, etc, and is famous for its library.

To the east of the City is the Port of London. Here, today, are miles and miles of docks and the great industrial areas that depend upon shipping. This is the East End of London, unattractive in appearance, but very important to the country’s commerce. There are a lot of factories, workshops and docks here. The streets are narrow, the buildings are unimpressive. The East End is densely populated by working class families.

The capital has 14 bridges, the famous London Bridge being the biggest among them.


Texts for home reading


Translate the following texts using a dictionary:




In common language, "weight" and "mass" are often spoken of as though they were the same things, and a body may be spoken of as "heavy" or "massive" interchangeably: even physicists some­times fall into a trap. However, consider what weight is. This weight of a body is the force with which it is attracted to the earth.

What will happen to the spring according to Hook's law? A simple way to measure the weight of an object is to suspend it from a coiled spring. In accordance with Hook's law the force by which the body is attracted to the earth will extend the spring, and the amount of the extension is proportional to the force. A weight-measuring device of this sort is a spring ba­lance.

The mass of a body, on the other hand, is the quantity of inertia it possesses. By Newton's second law: It is a force divided by an acceleration. Weight, which is a force, must by the same law be a mass multiplied by an acceleration. In the case of weight, which is the force of earth's gravita­tional field upon a body, the acceleration is, naturally, that which is produced by the earth's gravitational field.




Among the fundamental forces of nature, gravity is of spe­cial interest for several reasons. It is, first of all, the only truly universal force. It acts on every material thing from electron to galaxy, and, as we have learned in this century, it even acts on particles like photons and neutrinos or energy in any form. Second, gravity played a uniquely important role in the development and growth of mechanics. Newton, in his defini­tive formulation of mechanics, drew upon the studies of motion near the earth, influenced by local gravity, and of planetary motion far from the earth, influenced by the sun's gravity. Since Newton's time, motion governed by gravitational force has provided the strictest tests of mechanics, has served as stimulus for much of the mathematical elaboration of the theory of mechanics, has led to the discovery of distant new planets, and in own era of artificial satellites, has revealed new details of the shape and structure of the earth. Through the study of the orbit of Mercury came the first hint of an imperfection of Newtonian mechanics. Mercury's re­fusal to follow precisely the laws of classical mechanics stands now as one of the experimental supports of new mechanics of Einstein's general relativity.




Matter is made up of tiny particles known as atoms. There are only about a hundred different kinds of atoms, and they combine with each other in different ways to form groups called molecules. All matter is composed of atoms or molecules and some knowledge of how atoms are made will give us valuable in­formation about the behaviour of matter.

In 1911, Rutherford in England discovered that an atom has a tiny nucleus which is positively charged and contains nearly all the mass of the atom. Distributed about the nucleus and revolving about it in orbits are much less massive negatively charged particles called electrons.

In a normal atom, there are exactly as many negatively charged electrons as are needed to neutralise the positive charge of the nucleus, so that the atom as a whole is electrically neut­ral. This is of course also true of all normal material sub­stances, which are composed of atoms. The outermost electrons are less strongly bound to the atom than the inner ones, and they are the ones that take part in chemical reactions between atoms and that are responsible for the accumulation of an elec­tric charge on bodies.




The ancient Chinese knew that pieces of certain natural iron ores, when suspended by a string, take a definite position with one end pointing approximately north and the other approximate south. It is clear from the behaviour of the magnetic compass of loadstone and other magnets both natural and artificial.

We can use the magnetic field of the earth to magnetize steel rods if we hold them in the direction of the magnetic field of the earth and hitting them repeatedly with a hammer. The violent impacts shake the tiny particles of the rod and orient them, at least partially, in the direction of the field.

If we bring two magnetized steel rods close together, we find the ends pointed the same way during the magnetization process, to repel each other and if one of the rods is turned around, the ends of the rode attract one another.

This behaviour shows that a long piece of magnetized mate­rial - or a compass needle - shows its magnetic properties most strongly in the region near its end, known as the poles of the magnet. It also shows that like poles, i.e. poles that point toward this same direction, repel each other and that like poles attract.




The liquid state occupies an intermediate position between the gaseous and solid states, liquid having a definite volume but no definite shape.

Like a gas, a liquid can take the shape of any vessel in which it is put, but in contrast to a gas, a definite quantity of liquid is required for filling the vessel. A liquid can not be compressed so much as a gas because its molecules are alrea­dy close together, large pressure producing small changes in volume.

Increasing the temperature increases the kinetic energy of all molecules.

The change of a liquid into a gaseous or solid states being dependent upon the kinetic energy of the molecules, which in turn is dependent upon the temperature, there are definite temperature characteristics for most liquids at which these changes occur. They are known as transition temperatures.

If we place one liquid layer carefully on top of a layer of a more dense liquid in which it is soluble, and set the vessel where it won't be disturbed, we shall see that two liquids be­gin gradually mixing. It is also to be taken into consideration that all liquids do not flow with the same ease, water, alcohol, gasoline flowing easily, while heavy oil glycerine flowing very slowly.




If you take a paper clip and bend it it would stay bent, it wouldn't spring back and it wouldn't break. The metal of which the clip is made is ductile. Some other materials are not duc­tile at all. If you tried to bend a glass rod (unless you are holding it in a flame), it would simply break. It is brittle. In this respect as in many others, glass behaves quite different­ly from a metal. The difference must lie either in the parti­cular atoms of which metals and glass are made up or in the way they are put together, probably both. There are of course many other differences between metals and glass.

Metals, for example, conduct electricity and therefore are used for electrical transmission lines, glass hardly conducts electricity at all and can serve as an insulator. Glass being transparent, it can be used in windows whereas a sheet of metal even more than a millionth of an inch thick is quite opaque. It is of course interesting to understand the reasons of these differences in behaviour.

Solid-state physics is a major branch of science that has revealed new and previously unsus­pected properties in metals. It has become one of the most important branches of technology. It has given rise to technological progress. Having studied this branch of techno­logy, engineers could understand much better the phenomenon of quantum mechanics as it is applied to solids. Though solids, of course, were the subject of experimental investigation long be­fore quantum mechanics was invented.



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