英国学生科学读本 第64期:红色金属--铜(2)（在线收听） |
Copper can be rolled or hammered out into thin sheets, and so we say that it is malleable. It can also be easily drawn out into wire, and for this reason we call it ductile. Sheet copper is much used for covering the bottoms of ships, and for making kettles and saucepans and many other household articles. 经过碾压与捶打，人们就可以把铜制成薄片。因此，我们说，这种金属具有可锻性。通过拉伸，人们就可以获得铜线，因此我们说铜具有延展性。铜片可以用于覆盖船底以及制造水壶、炖锅与其他居家物品。
Copper is a good conductor of electricity—that is, it allows electricity to pass along it very easily. When electric lights or electric bells are put up, copper wire is always used. The cables which are placed on the bottom of the sea to carry telegraph messages from one country to another have copper wires running through them.
铜是很好的导电介质，也就是说，电流可以轻易通过这种金属。人们在电灯与电铃中总会使用到铜线。用于在不同国家之间传送电报信息的海底电缆也使用到了铜线。
Copper does not rust or tarnish so quickly as iron when exposed to the air. But if we heat a piece of sheet copper in a clear fire, we shall find that the surface turns black, from the copper rust which forms all over it.
与铁相比，如果暴露在空气之中，铜并不会那么快生锈与褪色。然而，如果我们使用明火对铜片进行加热，那么就会发现其表面从铜锈处开始变黑。
Copper is harder than lead, for we cannot scratch it with our finger-nail as we can scratch lead. But it is not so hard as iron, for it is easily scratched by an iron nail. Copper takes on a fine polish, and the surface of a piece of clean and polished copper is very bright.
铜的硬度比铅要高，因为与铅不同，我们无法用指甲在铜的表面刮出痕迹。不过它的硬度又比不上铁，因为我们可以用铁钉轻松地在铜的表面留下刮痕。铜的抛光性很好，一块经过抛光的纯铜表面能够呈现明亮的光泽。 |
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