Английский. пособие Химики АЯ. Introduction
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Unit 2. Fundamental Concepts of Chemistry Text 1 Active Vocabulary Periodic Law (phr) – периодический закон cornerstone (n) – краеугольный камень propose (v) – формулировать obtain (v) – предполагать atomic weight (phr) – атомный вес chemical relationships (phr) – химические связи family (n) – ряд similar (adj) – подобный point out (v) – указывать arbitrary (adj) – произвольный predict (v) – предсказывать 1. In pairs discuss the following questions. 1. Do you think chemistry is a difficult discipline? Give reasons. 2. What do you know about chemical elements? 3. Can you explain what the periodic table is used for? 2. Circle the correct word in the definitions below. If you are curious/ strange/ odd, you want to find out information about something. To find out or learn about a place, object for the first time means to become aware/ know/ discover. When a proper/ strict/ formal attempt is made, it is done officially. The effect or outcome of something is a result/ achievement/ success. If something occurs gradually/ suddenly/ rarely, it happens over some time. When two things relate/ interact/ determine, they react to one another. The word specific/ detailed/ thorough means exact. A shell/ nucleus/ atom is the hard outer part of something that protects what is inside. 3. What do you know about the Periodic Table? Who invented it? When? Read the text and find out. Periodical Table One of the cornerstones of modern chemical theory is the Periodic Law. It can be simply stated as follows: The properties of the elements are a periodic function of the nuclear charges of their atoms. History of the Periodic Table People have known about basic chemical elements such as gold, silver, and copper from antiquity, as these can all be discovered in nature in native form and are relatively simple to mine with primitive tools. Aristotle, a philosopher, theorized that everything is made up of a mixture of one or more of four elements. 0) D He also theorized that they change into new substances to form what we see. Hennig Brand was the first person to discover a new element. Brand was a bankrupt German merchant who was trying to discover the Philosopher's Stone – an object that is supposed to turn silver into gold. He experimented with distilling human urine until in 1669 he finally obtained a glowing white substance which he named phosphorus. 1) □ By 1809, a total of 47 elements had been discovered. As the number of known elements grew, scientists began to recognize patterns in the way chemicals reacted and began to devise ways to classify the elements. In 1817, Johann Döbereiner noticed that strontium had similar properties to calcium and barium, and that its atomic weight fell between them. 2) □ After compiling these, Döbereiner proposed that nature was made of triads of elements. He inferred that in a triad of elements, the middle element had the atomic weight of the average of the top and bottom elements' atomic weights. From this law, Döbereiner went on to discover the halogen triad composed of chlorine, bromine, and iodine and the alkali metal triad of lithium, sodium, and potassium. This idea of triads became a popular area of study. Following Döbereiner's work, a number of scientists subsequently discovered that chemical relationships can extend beyond triads. During this time, fluorine was added to the halogen group and oxygen, sulfur, selenium, and tellurium were grouped into a family, forming two tetrads; and nitrogen, phosphorus, arsenic, antimony, and bismuth were recognised as forming a pentad. Alexandre-Émile Béguyer de Chancourtois, a French geologist, was the first person to notice the periodicity of the elements — similar elements seem to occur at regular intervals when they are ordered by their atomic weights. 3) □ With the elements arranged in a spiral on a cylinder by order of increasing atomic weight, de Chancourtois saw that similar elements lined up vertically. His paper was published in 1862, but used geological rather than chemical terms and did not include a diagram; as a result, it received little attention until the work of Dmitri Mendeleev. John Newlands was an English chemist who wrote a paper in 1863 which classified the 56 elements that had been discovered at the time into 11 groups which were based on similar physical properties. 4) □ Newlands took Döbereiner's ideas and expanded on them. He also organized his elements by mass and property, but he added a twist. Döbereiner had worked only in small groups, but Newlands wanted to relate all the elements to each other. Newlands arranged the known elements in a table by atomic weights. In doing so, he noticed some recurring patterns, and the patterns were such that if he broke up his list of elements into groups of seven, the first elements in each of those groups were similar to one another, as was the second element in each group, and the third, and so on. 5) □ Newlands also noticed that silicon and tin formed part of a triad and so predicted a third unknown element with atomic weight of about 73, anticipating Mendeleev's prediction of germanium by six years, but did not leave a space for the new element in his table. Newlands' work was heavily criticised, even ridiculed, by other chemists, but he was finally awarded the Davy Medal by the Royal Society in 1887. Dmitri Mendeleev, also spelt Dmitry Mendeleyev, middle name Ivanovich, a Siberian-born Russian chemist, was the first scientist to make a periodic table much like the one we use today. 6) □ On March 6, 1869, a formal presentation was made to the Russian Chemical Society, entitled The Dependence Between the Properties of the Atomic Weights of the Elements. His table was published in an obscure Russian journal but quickly republished in a German journal, Zeitschrift für Chemie, in 1869. Mendeleev's paper was published only a few months before an independent paper by a German chemist, Julius Lothar Meyer, who had refined a more primitive table that he had originally drawn up in 1864. An English chemist, William Odling, also drew up a table that is remarkably similar to that of Mendeleev in 1864. Mendeleev predicted the discovery of other elements and pointed out that some of the then-current atomic weights were incorrect. He provided for variance from atomic weight order, left space for new elements, and predicted three undiscovered elements. 7) □ In 1913, Henry Moseley found a relationship between an element's X-ray wavelength and its atomic number. Previous to this, atomic numbers were just random numbers based on an element's atomic weight. Moseley's discovery showed that atomic numbers were not arbitrary but had an experimentally measurable basis. Mosley's research also showed that there were gaps in his table at atomic numbers 43 and 61 which are now known to be radioactive and not naturally occurring. 8) □ 4. Read the text again and choose from sentences, A– J, the one that best fits each gap 1– 8 to complete the text. There is one extra sentence you do not need to use. A He placed these three elements into a group, which he called a triad. B He kept his discovery secret, until 1680 when Robert Boyle rediscovered it and it became public. C His table did not include any of the noble gases, which hadn't been discovered. D He noted that many pairs of similar elements existed which differed by some multiple of eight in atomic weight. E Following in the footsteps of Dmitri Mendeleev, Henry Moseley also predicted new elements. F By analogy with the tonic musical scale of seven notes, which form octaves, he called his discovery the Law of Octaves. G Mendeleev arranged the elements in a table ordered by atomic mass. H They were fire, air, earth, and water. I He devised an early form of periodic table, which he called the telluric helix. J His confidence in the new classification was clearly expressed in the predictions which he made of the chemical properties of these missing elements. 5 (a). Give Russian equivalents for the following English words, word combinations and chemical terms. 1) be simply stated; 2) properties of the elements; 3) nuclear charges; 4) gold; 5) silver; 6) copper; 7) antiquity; 8) mine with primitive tools; 9) be made up of a mixture of; 10) be the first person to discover; 11) bankrupt; 12) to turn silver into gold; 12) name phosphorus; 13) a total of; 14) recognize patterns; 15) devise; 16) strontium; 17) fall between; 18) triads of elements; 19) average. 5 (b). Give English equivalents for the following Russian words, word combinations and chemical terms. 1) открытие; 2) строить теории; 3) относительно простой; 4) существовать; 5) состоять из; 6) область исследования; 7) признавать; 8) располагать в определённом порядке, последовательности; 9) увеличение атомной массы; 10) физические свойства; 11) группировать; 12) высмеивать; 13) составить таблицу; 14) длина волны; 15) изменение, колебание; 16) оставить место; 17) лакуна, пробел; 18) до, перед. 6. Identify the words, each dash stands for one letter only. Translate these words and make up your own sentences with them.
7. Fill in the appropriate word(s) from the list below into the text and then translate the sentences into Russian: problem, transformed, behaved, traces, isolation, nucleus, artificially, missing, to open up. Man at last understood the elements well enough to make his own. First there were some elements still ___1) from the Periodic Table. The fact was they were practically missing from nature, too. Scientists had to make these elements themselves. To make such elements meant first of all to carry on great experimental work. Many scientists worked hard at this ___2). In 1919 Ernest Rutherford was the first to change nitrogen to oxygen by bombarding nitrogen atoms with alpha-particles. To alter an element artificially is to add or subtract particles in its ___3). The first completely new man-made isotope was created by Rutherford's method, its creators being Irene Curie and her husband Frederic Joliot. To do that they had to bombard aluminium with alpha-particles. This attack ___4) some of the aluminium atoms into a highly radioactive substance. This substance was a new kind of phosphorus, its atomic weight being 30, instead of natural phosphorus 31. It was no wonder that phosphorus 30 did not occur in nature, its half-life being only two and a half minutes. Thus the Joliot-Curies were the first to produce "artificial radioactivity". The era of artificial transmutation began with the building of the first "atoms–masher", i. e. the cyclotron. By means of cyclotron and energetic particle–accelerators developed later it became possible ___5) the nucleus of any atom. It became possible to add particles to it, and even to create new ones. The first element produced in this way was the missing number 43, it being named "technetium" meaning "artificial". The aim of the scientists was to discover other elements. In 1939 a new element was found. It ___6) like an alkalimetal, therefore it was to be 87 the missing number of the alkali-metal family. It was called "francium". It was detected in nature. Later that element was produced ___7) by an accelerator, and only then did chemists obtain enough of it. For that reason francium is to be considered as a manmade element. Later scientists discovered ___8) of an element in neutron-bombarded uranium. They called it "neptunium". Radioactive neptunium gave rise to another element – number 94. In 1955 chemists could produce a few atoms of element 101, which was named "mendelevium" in honour of D. I. Mendeleyev. The ___9) of element number 102 occurred in 1963, it being named "nobelium", as part of the work was done at the Nobel Institute in Stockholm. 8. Give English translation for: К середине XIX века были открыты 63 химических элемента, и попытки найти закономерности в этом наборе предпринимались неоднократно. В 1829 году Дёберейнер опубликовал найденный им «закон триад»: атомный вес многих элементов близок к среднему арифметическому двух других элементов, близких к исходному по химическим свойствам (стронций, кальций и барий; хлор, бром и иод и др.). Первую попытку расположить элементы в порядке возрастания атомных весов предпринял Александр Эмиль Шанкуртуа (1862), который разместил элементы вдоль винтовой линии и отметил частое циклическое повторение химических свойств по вертикали. В 1866 году свой вариант периодической системы предложил химик и музыкант Джон Александр Ньюлендс, модель которого («закон октав») внешне немного напоминала менделеевскую, но была скомпрометирована настойчивыми попытками автора найти в таблице мистическую музыкальную гармонию. Д.И. Менделеев опубликовал свою первую схему периодической таблицы в 1869 году в статье «Соотношение свойств с атомным весом элементов» (в журнале Русского химического общества); ещё ранее (февраль 1869 г.) научное извещение об открытии было им разослано ведущим химикам мира. Сущность открытия Менделеева заключалась в том, что с ростом атомной массы химических элементов их свойства меняются не монотонно, а периодически. После определённого количества разных по свойствам элементов, расположенных по возрастанию атомного веса, свойства начинают повторяться. В 1871 году Менделеев сформулировал Периодический закон. В начале XX века с открытием строения атома было установлено, что периодичность изменения свойств элементов определяется не атомным весом, а зарядом ядра, равным атомному номеру и числу электронов, распределение которых по электронным оболочкам атома элемента определяет его химические свойства. Дальнейшее развитие периодической системы связано с заполнением пустых клеток таблицы, в которые помещались всё новые и новые элементы: благородные газы, природные и искусственно полученные радиоактивные элементы. 9. In pairs, discuss the following questions. 1. Besides the nucleus and electrons, what else is found in the atom? 2. Do you think scientists will discover any more elements? 10. Prepare a short presentation to answer the question: ‘What is the periodic table?’. Use the information of the text. Text 2 Active Vocabulary symbol (n) – знак, обозначение devise (v) – придумывать, изобретать concise (adj) – краткий recognizable (adj) – легко узнаваемый notation (n) – запись, изображение description (n) – описание indicate (v) – служить признаком, означать, кратко обозначить capital letter (phr) – прописная буква designate (n) – указывать, обозначать derive (v) – происходить subscript (n) – индекс electropositive (adj) – электроположительный distinguish (v) – различать 1. Read the headings A–E and the title of the text. What do you expect to read in the text? Read the text and check your guesses. 2. Read the text again and match the headings to each part of the text. There is one heading which you do not need to use. A Elements B Organic compounds C Inorganic molecules and compounds D A system of symbols and notation for the 106 chemical elements E Numerous chemical compounds Chemical Symbols and Formulas
This system of symbols, devised since about 1800 by chemists, consists of letters, numerals, and marks that are designed to denote the chemical element, formula or structure of the molecule or compound. These symbols give a concise and instantly recognizable description of the element or compound. In many cases through the efforts of international conferences, the symbols are recognized throughout the scientific world, and they greatly simplify the universal language of chemistry.
Of the 106 presently known chemical elements 105 have been given symbols, usually derived from the name of the element. Examples of names and symbols are chlorine, Cl; fluorine, F; aluminum, Al; oxygen, O; and carbon, C. However, symbols for some elements are derived from Latin or other names for the element. Examples are Au, gold (from aurum); Fe, iron (from ferrum); Pb, lead (from plumbum); Na, sodium (from natrium); and K, potassium (from kalium). The symbols consist of one or, more commonly, two letters. The first letter is always a capital letter and is followed by a lowercase second letter.
Simple diatomic molecules of a single element are designated by the symbol for the element with a subscript 2, indicating that it contains 2 atoms. Thus the hydrogen molecule is H2; the nitrogen molecule, N2; and the oxygen molecule, O2. Polyatomic molecules of a single element are designated by the symbol for the element with a numerical subscript corresponding to the number of atoms in the molecule. Examples are the phosphorus molecule, P4; the sulfur molecule, S8; and the arsenic molecule, As4. Diatomic covalent molecules containing unlike elements are given a similar designation. The formula for hydrogen chloride is HCl; for iodine monochloride, ICl; and for hydrogen iodide, HI. The more electropositive element is always designated first in the formula. For polyatomic covalent molecules containing unlike elements, numerical subscripts are used to designate the number of atoms of each element present in the molecule. Examples are phosphorus (III) chloride, PCl3; arsine, AsH3; ammonia, NH3, and water H2O. Again, as in diatomic molecules, the more electropositive element is placed first in the formula. Ionic inorganic compounds are designated by a similar notation. The positive ion is given first in the formula, followed by the negative ion; subscripts are again used to denote the number of ions of each element present in the compound. The formulas for several common compounds are sodium chloride, NaCl; ammonium nitrate, NH4NO3; aluminum sulfate, Al2 (SO4)3 and iron (III) oxide, Fe2O3. More complex inorganic compounds are designated in a manner similar to that above. The positive ion is given first, but may contain attached or coordinated groups, and this is followed by the negative ion. Examples are hexamminecobalt (III) chloride, [Co(NH3)6]Cl3; dichlorobis-(ethylenediamine) chromium (III) nitrate, [Cr(en)2, Cl2](NO3)3, where en is the abbreviation for ethylenediamine: and potassium trioxalatoferrate (III), K3[Fe(C2O4)3]. Hydrates of inorganic compounds, such as copper (II) sulfate pentahydrate, are designated by the formula of the compound followed by the formula for water, the number of water molecules being designated by a numerical prefix. Thus the symbol for the above compound is CuSO4* 5H2O.
Because there are many more organic than inorganic compounds, the designation or notation for the first group becomes exceedingly complex. Many different types of organic compounds are known; in the case of hydrocarbons, there are aromatic and aliphatic, saturated and unsaturated, cyclic and polycyclic, and so on. The system of notation used must distinguish between the various hydrocarbons themselves as well as setting this group of compounds apart from others such as alcohols, ethers, amines, esters, and phenols. Organic compounds can be designated by several different methods. The first is called the empirical formula method. Common examples are methane, CH4; ethane, C2H6; and ethyl alcohol, C2H6O. The disadvantage of this system is that it neither describes the structure of the particular molecule nor distinguishes between isomers. The second method consists of the designation of a compound by its structural formula. This method is illustrated by notation. There are many advantages of this method over the first. The exact structure, providing it is known, is given in a schematic representation. This removes any ambiguity concerning isomers or other structural variations. One of the disadvantages of the second method is that in many cases the structures cannot be on a single line of type. Special type is also needed for the various ring system and other complicating factors. To overcome this disadvantage, a third method, the line-formula designation, is used. Examples of this method are acetone, CH3COCH3; 3-chloropentane, CH3CH2CHClCH2 CH2; melamine, NC(NH2)NC(NH2)NC(NH2); and malonic acid. However, this method is cumbersome when used with complicated ring systems. |