Добавил:
Upload Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Сергейчик Учебное пособие.doc
Скачиваний:
0
Добавлен:
01.05.2025
Размер:
773.63 Кб
Скачать

XIV. Read the text using a dictionary. Discuss the chemical phenomenon described. Give your own example of a chemical change. What is a chemical change?

What is a chemical change? Let’s set up an apparatus with two test-tubes. In one of them there is a red powder which chemists call mercury oxide. We fill the other tube with water. When we heat the mercury oxide the bubbles of gas go up in this test-tube, and we can see little drops of silvery material gathering on the side of the tube with the red powder. This material is mercury. The second tube with the water now contains oxygen.

What has taken place in this experiment? We have broken up one substance into two. Mercury oxide is a compound. By means of heating we have separated the atoms of mercury and oxygen, and two substances different from the red oxide have appeared. These two substances are different from the original substance. They are also different from each other. Chemists called this type of transformation a chemical change.

XV. Speak on the topic “Chemistry as a Science”. Unit 3 d. I. Mendeleyev

  1. Study the topical vocabulary to avoid any difficulties in understanding the text in exercise IV. Consult a dictionary to pronounce the words correctly.

arrange v – располагать

award v – присуждать

consist (of) v – состоять (из)

degree nзд. степень

determine v – определять

be engaged in v – заниматься

enter (smth) vзд. поступать (куда-либо)

graduate (from) v – окончить

immense adj – огромный

obtain v – получать

predict v – предсказывать

property n – свойство

running g – руководство

thesis n зд. диссертация

weight n – вес, масса

II. Read the international words. Say what Russian words help to define their meaning. Consult a dictionary if necessary. Define the part of speech they belong to.

To lecture, medal, alcohol, calculation, to synthesize, to combine, laboratory, to analyze, experiment, vertical, horizontal, period, atomic, colossal, classification, idea, repetition, radioactive, majority.

III. Read and translate the sentences paying attention to the word result used as a noun or verb.

result n – результат

as a result – в результате

result v – получаться в результате

result in – приводить к (чему-либо), заканчиваться (чем-либо)

result from – получаться вследствие (чего-либо)

  1. The results of our experiments are published in a scientific journal.

  2. A chemical equation shows what substances react and what product results.

  3. The reaction of zinc with this acid results in the replacement of hydrogen atoms in the acid by zinc.

  4. Numerous experiments resulted in the discovery of a new radioactive element.

  5. As a result of these collisions new radioactive elements are formed.

  6. Transformations of some elements result in the release of atomic energy.

  7. The physical changes in the substance resulted from heating it.