Санкт-петербургского государственного университета высшее профессиональное образование т. А. Степанова, И. Ю. Ступина
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| Section III
Ex. 1. Think оГ the situations when a disjunctive question may be used, Examples: 1) She is the first-year student, isn’t she?— Yes, she is. You were absent yesterday, weren’t you? — Yes, I was. You have done the exercise, haven’t you? — Yes, I have. 2) She hasn’t finished her speech, has she? — No, she hasn’t. We haven’t yet studied such reactions, have we?—No, we haven’t Ex. 2. Translate the following questions into English. Let your fellow students respond to them. 1. Мы уже много знаем о водороде и кислороде, не правда ли? 2. Химические свойства щелочных металлов очень интересны, да? 3. Вы еще не закончили свою лабораторную работу, да? 4. Он прав, не правда ли? 5. Эта книга не очень трудна для вас, не правда ли? 6 . Вам нравится учиться, правда? 7. Она живет на Среднем проспек те, да? 8 . Вы уже видели своего преподавателя сегодня, да? 9. В ауди тории № 21 нет сейчас студентов, не правда ли? 10. У нас уже не осталось времени, да? Ex. 3. Make up sentences or short stories with the following words: 1 ) hydrogen, element, unit, other, be, it, use, lightest, mass chemical, measurement, element; 2) first, dissolve, iron, Cavendish, obtain, zinc, tin, hydrogen, acid, diluted, sulphuric; 3) be, clement, earth, hydrogen, abundant, spectrum, find, line, stars; 4) prepare, some, metal, at present, hydrogen, reaction, water Ex. 4. Give detailed answers to the following questions: 1. What arc the physical properties of hydrogen? 2. In what way was hydrogen obtained first? 3. What are the chcmical properties of hydrogen? 4. What do you know about the isotopic forms of hydrogen? 5. What arc the ways of obtaining hydrogen? Ex. 5. Discuss the following topics: 1. The Structure of a Hydrogen Atom. 47 2. Hydrogen as the Unit o f Measurement for the Masses of Other Elements. 3. The DifTcrcncc Between the Isotopic Forms of Hydrogen. 4. Commercial Obtaining o f Hydrogen. DO YOU KNOW THAT... In accordance with the theory of acids existing at that time, the result of the reaction o f inflammable air and oxygen was expected in the form o f an acid, but what Lavoisier obtained was only water. Later he learnt that Henry Cavendish in London had made similar experiments and had obtained water as a result of a combustion of the mixture of “inflammable air” and oxygen. Lavoisier repeated the experiment and made a striking discovery that water was not an element. And he gave “inflammable air” the name of hydrogen. жүктеу/скачать 5,96 Mb. Достарыңызбен бөлісу:
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