 |  | | | Picture 7. Copper's anti-bacterial and corrosion resistant properties help make it ideal for beer brewing vessels. |
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| | Corrosion resistant | | | | | | Copper is low in the reactivity series. This means that it doesn't tend to corrode. Again, this is important for its use for pipes, electrical cables, saucepans and radiators. However, it also means that it is well suited to decorative use. Jewellery, statues and parts of buildings can be made from copper, brass or bronze and remain attractive for thousands of years. | | | |
| Antibacterial | | | | | | Copper is a naturally hygienic metal that slows down the growth of germs such as E-coli (the “burger bug”), MRSA (the hospital “superbug”) and legionella.
This is important for applications such as food preparation, hospitals, coins (see biocidal copper), door knobs and plumbing systems.
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|  | | | Picture 8. Brazing copper pipes to make a strong joint. |
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|  | | | Picture 9. Brass can be polished up to give an attractive gold finish. |
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| | Easily joined | | | | | | Copper can be joined easily by soldering or brazing. This is useful for pipework and for making sealed copper vessels. | | | |
| Ductile | | | | | | Copper is a ductile metal. This means that it can easily be shaped into pipes and drawn into wires. Copper pipes are lightweight because they can have thin walls. They don't corrode and they can be bent to fit around corners. The pipes can be joined by soldering and they are safe in fires because they don't burn or support combustion. | | | |
| Tough | | | | | | Copper and copper alloys are tough. This means that they were well suited to being used for tools and weapons. Imagine the joy of ancient man when he discovered that his carefully formed arrowheads no longer shattered on impact. The property of toughness is vital for copper and copper alloys in the modern world. They do not shatter when they are dropped or become brittle when cooled below 0 °C. | | | |
| Non magnetic | | | | | | Copper is non magnetic and non sparking. Because of this, it is used in special tools and military applications. | | | |
| Attractive colour | | | | | | Copper and its alloys, such as brass, are used for jewellery and ornaments. They have an attractive golden colour which varies with the copper content. They have a good resistance to tarnishing making them last a long a time. | | | |
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| | | | | Picture 10. Roll over the properties above to see which metals give copper alloys those properties. |
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| | Alloys easily | | | | | | Copper can be combined with other metals to make alloys. The most well known are brass and bronze. Although copper has excellent electrical and thermal properties, it needs to be hardened and strengthened for many industrial applications. It is therefore mixed with other metals and melted. The liquid metals form a solution which, when they solidify, are called alloys. Some copper alloys are: - brass: copper + zinc
- bronze: copper + tin
- cupro nickel: copper + nickel
The alloys are harder, stronger and tougher than pure copper. They can be made even harder by hammering them - a process called work hardening. In ancient times, the first alloys could be made in the temperatures of a camp fire. This led to the Bronze Age. (see alloys and coins and extracting copper) | | | |
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|  | | | Picture 11. Copper hot water cylinders (background) are shredded and compressed into bales (front right) for recycling. |
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| | Recyclable | | | | | | Copper can be recycled without any loss of quality. 40% of the world's demand is met by recycled copper (see extracting copper). | | | |
| Catalytic compounds | | | | | | Copper can act as a catalyst. For example, it speeds up the reaction between zinc and dilute sulphuric acid. It is found in some enzymes, one of which is involved in respiration. So it really is a vital element. | | | |
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