Английский язык. Практикум по чтению научно-популярных текстов

1. The scientists could already present a true picture of an atomic structure in the 18th century. 2. An atom is referred to as the smallest particle of matter. 3. At extremely high temperatures molecules usually retain the properties of an element. 4. Every atom is only composed of a small nucleus. 5. The mass of an electron is extremely small compared with a nucleus. 6. The positive charge is concentrated in the space surrounding the nucleus. 7. It was discovered that the nucleus includes some particles of the same weight without any charge. 8. An atom gains a positive charge if it loses electrons. 9. An electric current can take place in any body if there is no difference of potential. 10. No current flows in a perfect insulator because there exists no free exchange of orbital electrons.

Ex. 18. Answer the following questions.

1.When did the development of a scientific atomic theory begin?

2.What is matter composed of?

3.What happens to molecules at extremely high temperatures?

4.What is an atom?

5.What is a space lattice?

6.What is the structure of an atom?

7.What is the charge of a nucleus (an atom)?

8.What happens if an atom gains (loses) an electron?

9.What is an electric current?

10.What happens to electrons in a conductor (an insulator)?

Ex. 19. Read the plan and rearrange it in the order the problems appear in the text.

1.Conductors and insulators.

2.Matter according to a modern atomic theory.

3.A charge of an atom.

4.The structure of an atom.

5.A free movement of electrons.

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Ex. 20. Retell Text 1 using the rearranged plan given above and the word combinations given below.

The development of a scientific atomic theory, to present a true picture, the smallest units, to form, a space lattice, to be arranged, a massive nucleus, positively (negatively) charged particles, a loose structure, electrons surrounding a heavy central core, to lose, to gain, a considerable excess of electrons, a free movement of electrons, to take place, an electric current, a free exchange of orbital electrons, to flow, a conductor, an insulator.

D. Further Reading

Ex. 21. Microscopy is a relatively young science but people have been interested in the micro world for a long time. Scan Text 2 to find the answers to the following questions.

1.What is microscopy?

2.When was the microscope invented?

3.How do microscopes differ?

4.What types of microscopes are mentioned in the text?

Ex. 22. Give the Russian equivalents of the international words.

Microscopy, optical, instruments, magnify, magnification, permanent, object (v), objective (n), modify, observe, observation, lens, combination, detect, intrigue (v), resolution, explore, illumination.

Ex. 23. Match the English word combinations with their Russian equivalents.

Ex. 24. Read Text 2 attentively for more information about microscopy.

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Text 2. IMAGING ATOMS

Observing and studying objects that range in size from millimeters to nanometers intrigues everyone. This fascinating science is called microscopy, currently applied to every field of science and technology from biology and chemistry to physics and engineering.

Many scientists today are working with single atoms or molecules. To do their work they have to be able to “see” molecules and atoms in some way. Optical instruments used for producing a magnified image of a small object are known as microscopes. The first compound microscope containing an objective lens system and an eyepiece system was created by a Dutch spectacle-maker Zacharias Janssen in 1595. It was simply a tube with lenses at each end. Having been modified and improved this microscope is most commonly used today giving us the possibility of viewing individual cells, even living ones, in two dimensions. Compound microscopes are light illuminated. Their high magnification is achieved by passing light reflected from the object through a combination of magnifying lenses. Unfortunately, the possibilities of light microscopes are limited by the resolution of the lenses being about 0.2 micrometer.

The resolving power can be significantly increased by using other types of microscopes. They come in a wide range of forms and use a multitude of illumination sources (light, electrons, ions, X-rays and mechanical probes) and signals to produce an image. An electron microscope, for instance, produces images by using electrons and electron lenses. A microscope similar to it in principal but using a beam of protons instead of electrons is known as a proton microscope. A device for viewing very small particles by observing the light from an intense beam scattered by them is called an ultraviolet microscope. The results of the observation are recorded with the help of a photo-micrograph – a photograph of the image obtained with the help of a microscope. This enables a permanent record to be kept and also enables ultraviolet radiation to be used for the illumination of the specimen. All modern powerful microscopes are combined with computers.

A microscope can be as simple as a handheld magnifying lens and as complex as a multimillion-dollar research instrument. Using these tools, a microscopist explores the relationship of structure and properties of a wide variety of materials in order to more fully understand the reasons why a particular item behaves the way it does.

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Ex. 25. Look through the text again and find words and phrases, which mean the same as following.

View (v), use (v), ray, union, a research device, for example, familiar, by means of, pattern, allow, study.

Ex. 26. Say if the following statements true or false. Prove your choice.

1.Microscopy studies measure units ranging from millimeters to nanometers.

2.Microscopy is not applied to mechanical engineering.

3.It is impossible to see an atom with a naked eye.

4.Modern microscopes do not have an objective lens system and an eyepiece system.

5.The first compound microscope was created in Holland in the 16th century.

6.Janssen’s original microscope is widely applied today.

7.The light microscope has a high magnification but a low resolution.

8.The sample can be illuminated by light, electrons, ions, X-rays and mechanical probes.

9.The results of the observation are recorded with the help of a microphotograph.

10.A simple microscope is a multimillion-dollar research instrument.

Ex. 27. Expand the statements given bellow with the information from the text.

1.Microscopy is fascinating.

2.Microscopy is useful.

3.The microscope is an instrument.

4.Zacharias Janssen was an inventor.

5.Microscopes vary.

6.A microscopist studies materials.

Ex. 28. Several types of microscopes are mentioned in the text. What are they? Fill in the table with their description.

Ex. 29. Translate the following texts in writing. Use the dictionary if necessary.

Text 3. ELECTRONS IN ORBIT

About 100 years ago Rutherford proved experimentally that the positively charged nucleus of an atom has negatively charged electrons re-

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volving round it and attracted to it. Later this theory was modified by Niels Bohr. The atom was pictured as a miniature solar system with the nucleus as the Sun and the electrons circulating around it as planets. This model reminds us that most of the atom is in fact empty space.

Later theories suggested that as the electrons spin round the nucleus thousands of millions of times every second and as the orbits are changing positions rapidly all the while, they might be better regarded as the “electron shells” round the nucleus. The shell model pictures the atom as a kind of microscopic onion with layer upon layer of electron shells.

In other models of the atom the shells have changed to “clouds” round the nucleus. Somewhere in one of these clouds you may find an electron.

Modern theories of the atom regard the electron both, as a particle and a wave.

Text 4. NUCLEAR CHEMISTRY

Atoms are known to undergo certain changes, however, which cannot be explained by changes in the configuration of atomic electrons.

H. Becquerel was the first to notice that a crystal of uranium salt placed on a photographic plate in the dark affected the plate so that an image of the crystal appeared. He concluded this effect to have been caused by the emission of some kind of ray from uranium.

Shortly after the discovery, the Curies found the intensity of the rays emitted by the pitchblende ore (урановая смоляная руда) from which uranium is obtained to be greater than would be expected.

The enhanced activity was proved to be due to a previously unknown element radium.

It was shown that the rays emitted by radium consist of two kinds of particles, called A-particles and B-particles, and an electromagnetic radiation called Y-rays, having a wave length of the same order as that of X- rays. A-particles have been shown to be the nuclei of helium atoms. They are emitted from radium with a speed of about 15 000 miles per second and are able to penetrate a few cm of air, or very thin aluminium foil.

B-rays are electrons; their speed is about 100 000 miles per second.

Unit II. New Materials and Their Properties

A. Pre-Reading

Ex. 30. Read the heading of the Unit. Investigate the idea of new materials.

a) Name some words and phrases related to new materials.

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b) Guess the meaning of these words.

Industrial, decade, nanometer, diameter, origin, original, disperse, colloid, sphere, pulverizer, reactive, inert, compact, combination, technique, unique, transparent, energetic, catalyst, synthesize, vacuum, extraordinary, basis, theory, definition.

Ex. 31. Learn to pronounce the words given below.

Enormous [i/no:məs], defining [di/faininiŋ], meter [/mi:tə], diameter [dai/æmi:tə], scale [skeil], disperse [dis/pə:s], powder [/paudə], sphere [/sfiə], pulverizer [/pΛlvəraizə], branch [bra:nt∫], inert [i/nə:t], technique [tek/ni:k], unique [ju:/ni:k], opaque [ou/peik], catalyst [/kætəlist], energetic [/enə/dʒetik], research [ri/sə:t∫], tube [tju:b], fiber [/faibə], synthesize [/sinѳisaiz], vacuum [/vækjuəm], reinforce [/ri:in/fo:s], envision [in/viʒən], aluminum [ə/lju:minəm], combustible [kəm/bΛstəbl], combustion [kəm/bΛst∫ən].

Ex. 32. Learn the words given below.

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Ex. 33. Give the Russian equivalents of these word combinations.

Composite and polymeric materials, an extraordinary characteristic of nanomaterials, the original branches of science, colloid chemistry, disperse particles, to pulverize a material, to demonstrate on a macroscale, unique techniques, catalytic properties, stable materials, the basis for a new era.

Ex. 34. Match the questions with the answers.

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B. Text Study

Ex. 35. Skim Text 1 to complete the following statements.

a)This text considers … .

b)It gives us some information about … .

c)It tells how … .

d)It discusses … .

Text 1. NANOMATERIALS

1.Over the past decades, nanomaterials have been the subject of enormous interest. These materials, notable for their extremely small size, have the potential for wide-ranging industrial, biomedical and electronic applications.

2.Nanomaterials can be metals, polymeric materials or composite materials. Their defining characteristic is a very small size in the range of 1...100 nanometers (nm). The unit of nanometer derives its prefix ”nano” from a Greek word meaning “extremely small”. By comparison, the diameter of a human hair is about 5 orders of magnitude larger than a nanoscale particle.

3.Nanotechnology as every thing in science has its origin and even a history. Nanomaterial science itself lies at the interfaces between material science, chemistry of solids and chemistry. The first branch of science that started working with particles of nano size was colloid chemistry. In 1857 M. Faraday investigated the properties of disperse gold obtained from a colloid solution. It was the first time when such small particles were studied. Methods of colloid chemistry are still used for obtaining nanopowders and other substances based on nanoparticles.

4.Another branch of science which achievements modern technology has been using is microscopy. In the period of 1920 wave theory of light was developed. The fact that electron can be rated as a wave opened new opportunities for microscopy. The source of light, used in microscope based on light optics, was replaced in a new microscope by the electron gun (source of electrons). These new microscopes were called electron microscope or Transmission Electron Microscope (TEM). Further development of this technology in 1930’s led to appearance of a new microscope – Scanning Electron Microscope (SEM).

5.Powder metallurgy was also a sphere of material science closely

connected to modern nanotechnology. This kind of metallurgy started its development in the middle of the 19th century. The main idea of powder metallurgy method is to pulverize a material and use special properties of

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small particles. One of the problem that nanotechnology faces is the high reactive rate of nanoparticles. The solution of this problem is to make nanopowders more compact. Methods used by powder metallurgy turn out to be suitable for nanomaterial science. As we can see nanomaterial science is a product of combination of methods adopted from different branches of science and technique.

6.Millions of people are sure that achievements of nanotechnology will influence scientific prosperity. Materials reduced to the nanoscale can suddenly show very different properties compared to what they exhibit on a macroscale, enabling unique application. For instance, opaque substances become transparent (copper); inert materials attain catalytic properties (platinum); stable materials turn combustible (aluminum); solids turn into liquids at room temperature (gold); insulators become conductors (silicon). Materials such as gold, which chemically inert at normal scales, can serve as a potent chemical catalyst at nanoscales.

7.The most energetic research probably concerns nanotubes. Nanoparticles of carbon – rods, fibers, tubes with single walls or double walls, open and closed ends, and straight or spiral forms – have been synthesized in the past 10 years. There is a good reason to devote so much effort to them: carbon nanotubes have been shown to have unique properties; stiffness and strength higher than any other material as well as extraordinary electronic properties. Carbon nanotubes are reported to be thermally stable in vacuum up to 2800 degrees Centigrade, to have a capacity to carry an electric current a thousand times better than copper wires, and to have twice the thermal conductivity of diamond (which also a form of carbon). Carbon nanotubes are used as reinforcing particles in nanocomposites, but also have many other potential applications. They could be the basis for a new era of electronic devices smaller and more powerful than any previously envisioned. Nanocomputers based on carbon nanotubes have already been demonstrated.

8.It is not surprising, then, that government bodies, companies, and university researches are joining forces or competing to synthesize, investigate, produce and apply these amazing nanomaterials.

Ex. 36. Scan the text in order to find

a)the information about the main characteristic of nanomaterials; their properties;

b)the evidence that carbon nanotubes have extraordinary electronic properties;

c)as many facts as possible to prove that nanotechnology is a combination of methods adopted from different branches of science.

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