专业英语练习答案2

Unit 1

IV

1. Chemical processes

2. Natural science

3. distillation

4. It is the atom that constitutes iron, water, oxygen etc.

5. Chemistry has a very long history, man's chemical activities can be

traced back to written times ago.

6. People learned that liquid could turn into gas (vapor) on certain condition in terms of distillation phenomena of water

7. You must understand a variety of properties of this material before using it.

V.

人们也许认为生命是三步进化的最终结果,第一步非常快,其余两步相当慢。这三步是：（I）物理进化（化学元素的产生），（II）化学进化（分子和生物分子的形成）；和（III）生物进化（有机物的形成和发展）。

全世界在实验室进行研究的化学家一直在努力回答这些问题，但学习普通化学的大部分学生不是化学专业。他们的兴趣在工程、生物学、物理学、卫生专业、地质学或农业。为什么许多不同兴趣的学生必须学习有关化学的内容呢？部分是因为能激发研究化学家兴趣的问题也可以激发许多其它人的兴趣，从生物学家、地质学家、工程师到政治家和有关的居民，更普遍的情况是自然存在的许多事物都存在重要的化学方面。从天气状况（模式）到大脑功能到电脑的操作，化学原理在任何事情中都起作用。Unit 6

V.

1. Metals combine very easy with other substances including oxygen in air, except for noble metals such as gold and platinum etc.

2. All metals, except for mercury, are solid at room temperature, and their atom arranged very regularly, often nearing tightly each other in order to occupy the smallest space.

3. Hydrogen is also an active element, therefore monomer hydrogen occurs seldom on the earth.

4. It is until 1854 or so that started to produce aluminium on commercial scale.

5.These two elements neither combine at normal temperature nor react evidently at high temperature.

6. The both are no-colour gases，which can be liquified like all gases.

7.It is very difficult that separate these two compounds even though possibility.

Unit7

1.Chemical formula

2.Structural formula

3.Chemical equation

4.Reversible reaction

5.Exothermal reaction.

6.Replacement reaction (double decomposition reaction)

7.displacement reaction (replacement reaction or metathetical reaction)

8.Sometimes equal is substituted for arrow,then it is supposed that the

direction of reaction is from left to right.

9.It is fully reasonable that these chemical reaction undergo in above

mentioned way

10.Each atom of element participated reaction changed form of

combination each other.

Unit 8

1. Matter can be neither created nor eliminated.

2. Scientist had to know how to apply number to obtain exact explanation for problem

3. Any matter,solid,liquid or gas, is all composed of atom.

4. We hope that scientists will be able to find (discover) more secrets about the universe.

5. The experiment is successful. Its result is the same as what we expected.

6. We will soon accomplish the test

7. People had learned to fire after many centuries

8. Teacher thinks that is very important to make student remember that two substances mixed simply may cause chemical change

9. More exploration of scientist for the secret of material interior make man more clearly find that the inner structure of the universe is reasonably and precisely arranged

10. Sound conducted by soft material similar to cloth is worse than by