在世界大大小小的比赛里，我们经常看到幸运者们满脸自豪地举起金灿灿的奖牌，这些金牌承载着荣誉与骄傲。然而金牌真的是用纯金做的吗？就让下面这篇文章来为你解答吧！

Actually gold medals are not made ofsolid gold. They consist of chiefly gold, and silver, copper and other metals. Why are gold medals not made of solid gold? The reason is that solid gold (the gold content is 99.99%) is too soft. A fingernail scratch would be able to damage the medal and it would lose its shape easily.

Twenty-four karat gold is solid gold. Those which add other metals are called k gold. The gold content of 1k gold is 4.1666%. Thus, we can calculate the gold content of all kinds of gold metals. The formula is the degree of k gold times the gold content of 1k. For example, there is a gold medal weighing 100g. The gold content of a 22k gold medal is 91.6652g. 24k gold is the maximum degree of k gold.

In daily life, the size and gold content of gold is decided by the law of competition and the importance of the programmers. The diameter of the biggest gold medal is 10cm so far, and the smallest one is about 1cm.

solid gold：纯金

（北京林业大学通讯员 邢元媛 供稿 英语点津 Annabel 编辑）