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          TED演讲:摩尔有多大(2)

          时间:2018-10-24 02:45来源:互联网 提供网友:mapleleaf   字体: [ ]
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            (单词翻译:双击或拖选)

             Now, back to the mole1. Not that mole. 现在,回到摩尔,不是鼹鼠。

            This mole. Yep, this number has a second name.The mole. 这个摩尔,没错,这个常数有另一个名字,摩尔.
            Chemists use the term mole to refer to the quantities that are at the magnitude2 of 602 sextillion. 化学家使用这个术语来表示602乘以10的21次方这个数量。
            This is known as a molar quantity. 就是大家知道的摩尔常数。
            Atoms and molecules3 are so small, that chemists have bundled them into groups called moles4. 原子和分子太小了,所以化学家将它们分成一群一群的,每一群就叫做一摩尔。
            Moles are hard for students to understand because they have a hard time picturing the size of a mole, or of 602 sextillion. 摩尔对于学生是很难了解的,因为他们很难想象一摩尔的数量,或是602乘以10的21次方。
            It's just too big to wrap our brains around. 它实在大到大?#38405;?#20197;理解。
            Remember our 18.01 milliliters of water? Well, that's a mole of water. 记得刚刚说的18.01毫升的水吗?那就是1摩尔的水。
            But how much is that? 但是这有多少?
            Exactly what does 602 sextillion look like? Maybe this'll help. 602乘以10的21次方看起来像什么?也许这个例子会有帮助。
            Exchange the water particles for donuts. 用甜甜圈来代替水分子。
            If you had a mole of donuts, they would cover the entire earth to a depth of eight kilometers, which is about five miles. 假如你有1摩尔的甜甜圈,它们会在整个地球表面堆高8公里,大约是5英里。
            You really need a lot of coffee for that. 你需要很多咖啡来配。
            If you had a mole of basketballs, you could create a new planet the size of the earth. 如果你有1摩尔的篮球,你可以制造和地球一样大的星球。
            If you received a mole of pennies on the day you were born 如果你一出生时有1摩尔的钱,
            and spent a million dollars a second until the day you died at the age of 100, 你每一秒花一百万直到100岁时死的那一天,
            you would still have more than 99.99% of your money in the bank. 你还有99.99%以上的钱在银行里。
            OK. Now we sort of have an idea how large the mole is. 好了,现在我们大概对1摩尔有个概念了。
            So how do we use it? 那么我们如何用它?
            You might be surprised to know that chemists use it the same way you use pounds to buy grapes, deli meat, or eggs. 你也许会惊?#28982;?#23398;家使用它的方法,就如同你用磅来买葡萄、熟食肉类或鸡蛋。
            When you go to the grocery store, you don't go to the deli counter and ask for 43 slices of salami,  当你到杂货店时,你不会走到柜台要43片腊肠,
            you buy your salami by the pound. 你会买几磅的腊肠。
            When you buy your eggs, you buy a dozen eggs. 当你买鸡蛋时,你会买一打鸡蛋。
            When we hear the word dozen, we probably think of the number 12. 当我们听到打这个字,我们会想到数字 12。
            We also know that a pair is two, a baker's dozen is 13, a gross5 is 144, and a ream of paper is...anybody? 我们也知道一双就是2,面包师父的一打是13,一箩是144,一令纸......谁知道?
            A ream is 500. Well, a mole is really the same thing. 一令纸是500张。一摩尔也是一样的。
            For a chemist, a mole conjures6 up the number 6.02 times 10 to the 23rd, not a fuzzy little animal. 对化学家而言,1摩尔就是6.02乘以10的23次方,而不是毛绒绒的动物。
            The only difference is that the other quantities are more famili ar to us. 唯一的差别是我们比较熟悉其他的计数单位。
            So there you have it. The story of the mole, Avogadro, basketballs, and how to buy salami at the grocery store. 现在你知道了摩尔的故事、阿伏加德罗、篮球、还有去杂货店怎么买腊肠了。

          点击收听单词发音收听单词发音  

          1 mole 26Nzn     
          n.胎块;痣;克分子
          参考例句:
          • She had a tiny mole on her cheek.她的面颊上有一颗小黑痣。
          • The young girl felt very self- conscious about the large mole on her chin.那位年轻姑娘对自己下巴上的一颗大痣感到很不自在。
          2 magnitude ek5yY     
          n.大小;重大;星等
          参考例句:
          • I want to know the magnitude of this equipment.我想知道这个设备的大小。
          • I hadn't realized the magnitude of the problem.我没有认识到这个问题的重要性。
          3 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
          分子( molecule的名词复数 )
          参考例句:
          • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
          • Inside the reactor the large molecules are cracked into smaller molecules. 在?#20174;Χ牙錚?#22823;分子裂变为小分子。
          4 moles 2e1eeabf4f0f1abdaca739a4be445d16     
          防波堤( mole的名词复数 ); 鼹鼠; 痣; 间谍
          参考例句:
          • Unsightly moles can be removed surgically. 不雅观的痣可以手术去除。
          • Two moles of epoxy react with one mole of A-1100. 两个克分子环氧与一个克分子A-1100?#20174;Α?
          5 gross cyEys     
          adj.全部的,粗俗的,肥胖的;vt.获得...总收入
          参考例句:
          • The gross weight of the box of chocolates is 500 grams.那盒巧克力的全部重量是500克。
          • I consider this a gross oversight on your part.我把这件事看作是你的一大疏忽。
          6 conjures 6e9034d987393ecf704e5c3a4c34247b     
          用魔术变出( conjure的第三人称单数 ); 祈求,恳求; 变戏法; (变魔术般地) 使…出现
          参考例句:
          • The word 'birthday' conjures up images of presents and parties. “生日”这个词使人想起礼物和聚会的情景。
          • The name Sahara conjures up images of a desert of aridity. "撒哈拉"这个名字使人想起干旱的沙漠情景。
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