时差N小时 可乐除铁锈（上）（在线收听）

Let's begin with a cleaning tip:

先分享一个去污小妙招：

If you have some tarnished or corroded brass that you want to clean, an old brass candlestick for example,

如果你想要清除铜锈，例如铜烛台，

you can use Coca-Cola, or any other cola soft drink, and that brass will come clean.

可以使用可口可乐或者其它可乐饮料，清洗后的烛台光亮如新。

And if Cola is such an effective cleaner of corroded metal, what is it doing to the inside of your stomach?

如果可乐能有效清洁金属锈斑，那么可乐对人体的胃会产生什么影响呢?

Cleaning with Cola on today's moment of science.

今日科学一刻：用可乐清洗物品

Cola cleans brass because it's mildly acidic.

可乐能清洁铜锈是因为可乐呈弱酸性。

Here's what happens: When brass or another metal alloy becomes tarnished,

经常遇到这种情况：当黄铜或其他金属生锈时，

this means that there has been a chemical reaction between the oxygen in the air and one of the metals in the alloy.

是因为空气中的氧气和合金中的某种金属发生了化学反应。

Oxygen atoms combine with metal atoms to form what's called an oxide, and this oxide is what makes the metal appear tarnished.

氧原子结合了金属原子，形成所谓的氧化物。氧化物就是金属锈。