Л.Ш. Атабаева - Английский язык. Технические факультеты и специальности (1254789), страница 22
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In turn, these develop123ments helped them to develop quantum mechanics – the basis of both modern chemistry and physics.In chemistry, the atom is the smallest part of an element that can still berecognized. An example will explain best of all. Each element is identifiedby the number of protons it has. An atom of carbon has six protons. Thosesix protons without the neutrons and electrons, or the electrons without theother subatomic particles are simply subatomic particles; they are not carbon. A carbon atom can be combined with two atoms of oxygen to give thecompound carbon dioxide, or C02. It is this difference in the number of subatomic particles that makes one atom different from another.Subatomic particles also have another purpose.
If there is the samenumber of electrons and protons in the atom, then the atom will be electronically neutral. A difference between the two means the atom has an electrical charge, in other words, it produces electricity. This electricity means theelectrons can become attracted to each other. In this way, atoms can bondtogether to form molecules, and when enough molecules are joined togetherwe have matter that we can see.The most recent theories of the origin of the universe say that all theatoms in the universe were formed in the first few minutes of the universecoming into existence.
The most common element is the simplest, hydrogen, which has the atomic number 1. Seventy-five per cent of all atoms arehydrogen atoms. The next most simple is the next most common, helium,atomic number 2 making twenty-four per cent of all atoms. All the otheratoms add up to just one per cent of everything that exists in the universe.Vocabulary1.
separation2. matter3. to hypothesize4. to exist5. to accept6. compound7. to recognize8. particle9. to attract10. bondpазделениевещество, материалстроить гипотезусуществоватьприниматьсоединениепризнаватьчастицапритягиватьсоединять124Vocabulary development3.3. Read the following international words and check their pronounciation in a dictionary.Carbon dioxide, electron, helium, hydrogen, molecule, neutron, proton,quantum mechanics, subatomic, universe3.4.
Match these words with their definitions.1. subatomicA) part of an atom which has no charge2. electronB) two or more atoms3. neutronC) smaller than an atom4. moleculeD) part of an atom that has a negative charge5. protonE) a theory developed by physicists to explain the atom6. quantum mechanics F) part of an atom which has a positive charge7. carbonG) pulled together8.
attractedH) a chemical element9. heliumI) a chemical element that is lighter than air10. universeJ) the whole cosmosComprehension3.5. Choose the correct answer and complete the sentences.1. Dalton believed the atom to beA) an element.B) made of smaller particles.C) the smallest possible particle.D) his own idea.2. Dalton's theories wereA) generally accepted.B) not tested very carefully.C) accepted at once.D) not correct.3. The number of protons in an elementA) is the same as the number of electrons.
B) is always six.C) never changes.D) characterizes the element.4. Electrons helpA) protons to form elements.B) atoms to be neutral.C) molecules to become atoms.D) atoms to form molecules.5. Hydrogen isA) the simplest atom there is.B) present in all atoms.C) the oldest atom.D) as common as helium.Writing3.6. Write a short essay on the steps of atom structure study (80-100words).125Unit 4Before you read4.1. Answer the following questions.1.
Your future research work will be connected with optical devices,namely lasers. What is LASER?2. What types of lasers exist?4.2. Give the translation of the following terms from the text below. Usethe dictionary if necessary.1. energized atoms8. gas lasers2. light amplification9. visible red light3. stimulated emission10. semiconductor lasers4. exited state11. dye lasers5. light released12.
diode lasers6. solid state lasers13. use low power7. pumped14 discharge4.3. Read the text and find the answers to the questions of 4.1.LASER BASICSLasers play a pivotal role in our everyday lives. The fact is they show upin an amazing range of products and technologies. You will find them ineverything from CD player to dental drills, from high-speed metal cuttingmachines to measuring systems.
Tattoo removal, hair replacement, eye surgery – they all use lasers. But what is a laser? What makes a laser beam different from the beam of a flashlight? What are the main types of lasers?Let‟s start with the fundamentals of laser technology.A laser is a device that controls the way that energized atoms releasephotons.”Laser” is an acronym for light amplification by stimulated emission of radiation.
In a laser, the lasing medium is “pumped” to get the atomsinto an exited state. Typically, very intensive flashes of light or electricaldischarges pump the lasing medium and create a large collection of exitedstate atoms (atoms with higher-energy electrons). It is necessary to have alarge collection of atoms in the exited state for the laser to work efficiently.Laser light has the following properties:– the light released is monochromatic it contains one specific wavelength of light (one specific colour);– the light released is coherent it is “organized” – each photon moves in126step with the others;– the light is very directional.
A laser light has a very tight beam and isvery strong and concentrated. A flashlight, on the other hand, releases lightin many directions and the light is very weak and diffuse. To make thesethree properties occur takes something called stimulated emission. This doesnot occur in your ordinary flashlight – in a flashlight, all of the atoms release their photons randomly. In stimulated emission, photon emission isorganized. The other key to a laser is a pair of mirrors, one at each end ofthe lasing medium. In the process, they stimulate other electrons to make thedownward energy jump and cause the emission of more photons of the samewavelength and phase.There exist some different types of lasers.
The laser medium can be asolid, gas, liquid or semiconductor. Lasers are commonly designed by thetype of lasing material employed.Solid-state lasers have lasing material distributed in a solid matrix (suchas the ruby).Gas lasers (helium and helium-neon are the most common gas lasers)have a primary output of visible red light.Excimer lasers (the name is derived from the terms excited and dimers)use reactive gases (chlorine) mixed with inert gases (argon and xenon).Dye lasers use complex organic dyes in liquid solution as lasing media.Semiconductor lasers or diode lasers. These electronic devices are verysmall and use low power.Thus, a laser is created from light, and the resulting laser light has special properties that are unique and different from regular light.
A laser canbe of different types and strengths. A laser can be very tiny so as to be almost invisible, and can be very large so as to occupy an entire room. Thelaser is indeed a very useful and exciting invention, with many beneficialapplications and uses.Vocabulary1. emit (v)2.
emission (n)3. emitted (adj)4. release (v)5. amplify(v)6. amplification (n)7. stimulate (v)8. wavelength (n)испускать, излучать (свет)испускание (света), эмиссияизлученныйиспускать, выбрасыватьусиливатьусилениевозбуждать, индуцироватьдлина волны1279. flashlight (n)10. output (n)11. lasing medium12. lasing materialзонемигающий свет, электрический фонарикмощностьсреда, генерирующая в оптическом диапазоневещество, излучающее в оптическом диапа-4.4.
Match the fields of laser applications with their definitions.1. dental drillsa. To put hair back to its proper place2. tattoo removalb. Medical operation on people‟ s eyes3. high-speed metal cutting c. A small, high-speed tool used in dentistry to remove decayed tooth materialprior to the insertion of a dental filling4. hair replacementd. The process of taking away a permanent picture drawn on a part of yourbody by putting ink into your skin witha needle.5. eye surgerye. Very quick operations aimed at dividing metal material into pieces4.5.
Match the words similar in the meaning.1. extremelya. straight2. efficientb. dispersed3. extraordinaryc. unplanned4. move in stepd. pivotal5. tighte. amazing6. diffusef. operate in conformity7. randomlyg. effective4.6 Read the text 4.3 again and answer the following questions.1. What is a laser?2. What fields of human activity are the lasers used in?3. What is the difference between regular and laser light ?4. What types of lasers have you learned about from the text?5. What do you think about the prospects of laser applications?128Unit 5Before you read5.1.
Read and memorize the following terms.1. fiber/fibre (n)волокно2. fiber opticsоптоволоконная техника3. loss (n)потери4. immune (adj)устойчивый5. interference (n)помехи, интерференция6. bandwidth (n)ширина полосы пропускания7. sensor (n)датчик8. remote sensingдистанционное считывание9. bundle (n)пучок, группа10. network k(n, v)сеть; создавать/подключаться к сети11. propagate (v)распространять(ся)12. attenuation (n)затухание13. repeater (n)ретранслятор14. duct (n)канал15. cross-talk (n)помехи, перекрестные искажения16. pick up of smthулавливание (зд .шума)17. ignition (n)воспламенение, возгорание18.
modulate (v)модулировать, понижать частоту19. light guide (n)световод20. imaging deviceустройство изображения21. gain mediumрабочая среда лазера22. route (v)направлять5.2. Match the words with their definitions.1. fibrea. to change something, especially in order to achieve someeffect2. fibre optics b.
a very thin piece of natural or artificial substance3. sensorc. the reduction of strength, amount or size of something4. bundled. the use of long fibres of glass or plastic to carryinformation as light signals5. immunee. a piece of equipment that reacts to physical changessuch as amount of heat, light, etc.6. lossf.
a group of things that have been tied or connectedtogether1297. networkg. not influenced or affected by something8. attenuation h. to connect computers together so that each computer cansend and receive information9. modulatei. the state of having less of something than before.5.3. Read the text and find the answers to the following questions.1. What is an optical fibre?2. Where can optical fibres be used?3. What are the advantages of optical fiber over electrical cables?OPTICAL FIBER AND ITS USEAAn optical fiber (or fibre) is a glass or plastic fiber that carries lightalong its length.
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