Санкт-петербургского государственного университета высшее профессиональное образование т. А. Степанова, И. Ю. Ступина
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1stepanova t a english for chemists
| Section II
Упр. 1. Назовите значения следующих интернациональных слов: diffraction, magnetic, dipole, moment, interpretation, resonance, entropy, information, configuration, quantum, mechanics, anticipate, discussion Упр. 2. Определите значения выделенных слов по контексту. 1. Properties of an element are due to the composition and structure of its atom. 2. Our laboratory is provided with all the ncccssary chcmicals and dcviccs. 3. It is not always easy to give a complete characteristic of a compound. 4. X-rays arc sometimes callcd Rdntgcn rays. 5. In a molccular spcctrum a scries of rather broad bands is formed, that is why it is callcd band spcctrum. 6. It is ncccssary to take into account the unusual properties of the compound. Слова к тексту: w ith respect (о — в отношении чего-л.; w ave — волна; n u c le a r — ядер- ный; refin em en t — усовершенствование; d isp erse — рассеивать; veil — по кров, завеса; m y s(e ry — тайна; sh ro u d — окутывать Text 19 В Прочтите текст про себя (контрольное время чтения — 3 минуты). The Development of the Theory of Valence Modem structural chcmistry differs from classical structural chcmistry with respect to the detailed picture of molecules and crystals that it presents. By various physical methods, including the study of the structure of crystals by the diffraction of X-rays and o f gas molcculcs by the diffraction of clcctron waves, the measurement of electric and magnetic dipole moments, the interpretation of band spectra, line spectra, microwave spectra, and nuclear magnetic resonance spectra, and the determination of entropy values, a great amount of information has been obtained about the atomic configurations o f molcculcs and crystals and even their electronic 134 structures; a discussion of valcncc and the chcmical bond now must take into account this information as well as the facts of chcmistry. The rcfinmcnt of the electronic theory of valcncc into its present form has been ducf almost entirely to the development of the theory of quantum mechanics, which has not only provided a method for the calculation of the properties of simple molcculcs, leading to the complete elucidation of the phenomena involved in the formulation of a covalcnt bond between two atoms and dispersing the veil of mystery that has shrouded the bond during the dccadcs since its existence was first assumed, but has also introduced into chcmical theory a new conccpt, that o f resonance, which, if not entirely unanticipated in its applications to chcmistry, nevertheless, has not before been clcarly rccognizcd and understood. Упр. 3. Перелайте основное содержание текста в несколькнх пред ложениях. Упр. 4. Составьте план текста. Упр. 5. Прочтите предложения н скажите, соответствуют ли онн со держанию текста. Если нет, исправьте их. 1. Structural chcmistry hasn’t changed since the 19th ccntury. 2. The pictures of molcculcs presented by modem chcmistry and classical structural chcmistry arc not the same. 3. Electronic structures arc investigated only by chcmical methods. 4. The development o f the theory o f quantum mechanics affcctcd the refinement of the electronic theory. 5. A conccpt of rcsonancc was introduced in terms o f the theory of quantum mechanics. 6. Application o f quantum mechanics enabled scientists to develop a method for the calculation of the properties o f simple molcculcs. Упр. б. Найдите в тексте описание различий между современной •' структурной химией и классической и переведите эти предложения на русский язык. жүктеу/скачать 5,96 Mb. Достарыңызбен бөлісу:
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