III. Read the text attentively for more information about copper.

Copper is man's oldest metal as people could extract it more than 10,000 years ago. As it is rather soft and ductile, copper is alloyed with other elements. There is evidence that the first copper alloy – bronze (90% copper, 10% tin) – was produced around 2800 ВС in countries such as India, Egypt and Mesopotamia. Bronze was harder and could be used for making reliable cutting tools. Its use charac­terizes the Bronze Age.

The workability and the ability for corrosion resistance made cop­per, bronze and brass the most important functional as well as deco­rative materials from the Middle Ages and on till the present day. With the beginning of the Electrical Age the demand for copper increased tremendously because it is an unusually good conductor of electricity and heat. Today more than 5 million tons of copper are produced annually and the copper metals are playing an increasingly vital part in all branches of modern technology.

The good news is that we will not run out of copper. The worldwide resources of this important and valuable metal can be estimated at nearly 5.8 trillion pounds of which only about 0.7 trillion (12%) have been mined throughout history. Besides, nearly all of 700 billion pounds is still in circulation because copper's recycling rate is high­er than that of any other engineering metal. Each year nearly as much copper is recovered from recycled material as is obtained from newly mined ore. Almost half of all recycled copper scrap is old post-consumer scrap, such as discarded electric cable, junked automobile radiators and air conditioners, or even ancient Egyptian plumbing! The remainder is new scrap, such as chips and turnings from screw machine production. Engineers hope that we will be able to use copper for centuries on.

IV. Say if the following statements are true or false. Correct the false statements.

1. Copper was extracted by man more than 10,000 years ago.

2. Copper alloys appeared because there was shortage of pure copper.

3. Copper metals are important functional and decorative materials today.

4. In the 19th century the demand for copper greatly decreased.

5. The resources of copper will be worked out in the near future.

6. If Egyptian plumbing is recycled a lot of copper can be obtained.

 

V. Agree or disagree with these statements. Give reasons for your answer.

1. Copper metals possess valuable properties.

2. Technological progress increases the demand for copper.

3. There is no need to save copper resources.

4. Copper can and should be recycled.

VI. Complete the diagram that classifies the following engineering materials. The diagram should have three levels.

alloys

copper

brass

pure metals

metals

bronze

tin

VII. Give a title to the text.

Activity

I. a) Divide into groups and fill in the table using the information from the text and your background knowledge.

Copper Metals

Area of Application	Example	Necessary Properties
Medical Engineering	…	biostatic, corrosion-resistant
…	…	…

b) Compare your results. Which group has the longest list?

 

II. You have been invited to a conference on the advances in Materials Science. Prepare a report on the topic. "Present-day application of copper " and deliver it in class. Choose the most interesting one.

Writing

I. Study the table and write a paragraph about the appli­cations and properties of various copper alloys.

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