TheCleaningPowerofSoftDrinks!

1、 普特英語聽力 免費學(xué)習(xí)英語The Cleaning Power of Soft Drinks!飲料的神奇清潔能力Lets begin with a cleaning tip: If you have some tarnished or corroded brass that you want to clean, an old brass candlestick for example, you can use Coca-Cola, or any other cola soft drink, and that brass will come clean.How Does This Work?A

2、nd if Cola is such an effective cleaner of corroded metal , what is it doing to the inside of your stomach?Cola cleans brass because its mildly acidic.Heres what happens: When brass or another metal alloy becomes tarnished, this means that there has been a chemical reaction between the oxygen in the

3、 air and one of the metals in the alloy.Oxygen atoms combine with metal atoms to form whats called an oxide, and this oxide is what makes the metal appear tarnished. Acids, like the weak acid present in your can of Coke, can react with oxides to effectively reverse the process of tarnishing. The aci

4、d dissolves the metal oxides that make the tarnish, leaving only shiny metal behind.Try It At Home!You can try this at home, even if you dont have a brass candlestick. Leave a tarnished old penny in a glass of cola overnight. In the morning it will be shiny and fresh.Your Stomach And AcidIf the acid

5、 in cola is so good at attacking tarnished metal, what might it do to your insides? Actually, your stomach already contains its own supply of acid which it uses to digest food.This stomach acid is a great deal stronger than the acid in a can of Coke. Indeed, stomach acid would be an even better tarn

6、ish remover than cola!有個去污點子：如果你想要清除銅銹，例如銅燭臺，可以使用可口可樂或者其它可樂飲料，清洗后的燭臺光亮如新。飲料是如何清潔的呢?如果可樂能有效清潔金屬銹斑，那么可樂對人體的胃會產(chǎn)生什么影響呢？可樂能清潔銅銹是因為可樂呈弱酸性。銅或其它金屬合金生銹是因為空氣中的氧氣和合金中的某種金屬發(fā)生了化學(xué)反應(yīng)。氧原子結(jié)合了金屬原子，形成所謂的氧化物。氧化物就是金屬銹。而酸，比如可樂中的弱酸，和氧化物產(chǎn)生化學(xué)反應(yīng)，能有效避免生銹。酸可以分解金屬氧化物，化學(xué)反應(yīng)后的金屬锃亮。在家試驗即便家里沒有銅燭臺，你可以做這樣的試驗：晚上，將一枚舊硬幣丟進裝有可樂的杯里。第二天早上，硬幣就變得閃亮如新。酸