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老河口市第一医院怎么样襄阳中西医结合医院做孕检多少钱Hi, Im Jessica 嗨,我是Jessicaand today Im gonna talk about a reaction I like to call今天我要讲的化学演示叫作;Midas magic; ;迈达斯的魔术;and before I get started, lets watch the reaction in action在开始之前,我们先来看看实际反应with the help of Dr. Bassam Shakhashiri 演示由Bassam Shakhashiri士来做and here he is 这就是他了hes actually the president of the American Chemical Society他是美国化学学会主席and his motto is science is fun他的格言是,科学很有趣Here he is at MIT and lets see what he has to show us他来到MIT,看他是怎么做的Watch this. I take this clear and colorless liquid看这个,这是一种无色透明液体and I put some of it into beaker, about 100 milliliters将一些倒入烧杯,大约100毫升How do I know its about 100 milliliters?我怎么知道大约是100毫升Im ing the markers here on the beaker 我阅读了烧杯上的刻度and I take about 100 milliliters of a bit different clear and colorless liquid 再倒100毫升的另一种无色透明液体but you dont know its different, they look the same但你们不知道它不同,因为看起来是一样的and look at this look, look whats gonna happen now? 看这个,看看会发生什么Isnt one of the most fascinating observations you make?这非常迷人,不是吗You take 2 clear colorless liquid, you mix them together将两种无色透明液体混合and you get a yellow substance that is insoluble in water 却得到了一种不溶于水的黄色物质This is lead iodide这是碘化铅I mixed potassium iodide solution with lead nitrate solution我混合了碘化钾溶液和硝酸铅溶液So the magician never tells you how the trick works 魔术师不会告诉你们为什么会这样but in science we like to know whats going on 但科学中,我们会解释发生了什么So what is going on? Lets break it down发生了什么呢,我来讲解一下Dr. Shakhashiri started with two clear colorless liquidsShakhashiri士使用了两种无色透明液体He had about 100 milliliters of lead nitrate 他用了大约100毫升的硝酸铅and that aqueous, its in solution 这是溶于溶液的and about 100 milliliters of potassium iodide还有大约100毫升的碘化钾also aqueous 也是溶液状态and when he mixed those together将两者混合he got a yellow precipitate 他得到了黄色沉淀Lets color that in yellow我用黄色来表示A precipitate is a solid沉淀物是一种固体So how do we know what this yellow solid is?我们怎么知道这种黄色固体是什么呢Well, this is a reaction thats called a double displacement reaction这种反应被叫作复分解反应And in this kind of reaction这种反应中the cation and anion pairs switch places阳离子和阴离子相互交换So what exactly does that mean? 什么意思呢Im gonna use some colors to help me out我将用些色来描述So weve got cations and anions in each of these compounds 这两种化合物中都有阳离子和阴离子The cations have positive charge, so阳离子具有正电荷in this case its led which has a 2+ charge 这里铅离子具有2+电荷and nitrate, N03-然后是硝酸根离子 NOYou need 2 of those to have a neutral compound 这需要两个,才能得到中性化合物Our other compound over here has potassium这里另一种化合物拥有钾离子which has a +1 电荷是+1an our anion is iodide 而阴离子是碘离子which is -1 电荷是-1201412/351131鱼梁洲开发人民医院怎样 Kaki King 摇滚演奏 “粉红噪音”201501/352822Jasmine Orchard shows how to turn trash into treasure. In this , turn a candelabra and other odds and ends into a beautiful cake stand fit for even the finest Victoria sponge.Jasmine Orchard向你展示怎样变废为宝。在这段视频中,用一个枝状大烛台和其他零碎物品制作一个漂亮的蛋糕架,适合各种场合使用。You Will Need你需要candelabra枝状大烛台white spray paint白色喷漆2 tray/plates2个托盘/盘子glue胶水Step 1: Paint the Candelabra1.为烛台喷漆Take your white spray paint and spray the candelabra. Leave to dry.用白色喷漆为烛台上漆。等待油漆变干。Step 2: Glue the Cake-Stand Together2.粘合Glue the base of the candelabra and attach your base plate/tray. Leave to dry. Add some glue to the top of your candelabra. Add a smaller plate/tray to the top of your candelabra and glue. Leave to dry.用胶水把烛台底部和盘子底部粘合在一起。待其变干。在烛台顶部抹一些胶水。在烛台顶部放一个较小的盘子,粘在一起。等待其变干。Step 3: Serve Some Cakes3.奉上蛋糕Add some cakes to the top of your stand and bask in the Edwardian luxury of it all.在蛋糕架上摆放一些蛋糕,精心招待你的朋友。Thanks for watching How To Make A Cake Stand.感谢收看“怎样制作蛋糕架”视频节目。视频听力栏目译文属。201307/246276襄阳泌尿科体检多少钱

襄阳市中心医院北区陈医生襄樊哪里看阳痿早泄有效 襄樊人民医院属于私人医院吗

襄阳哪家医院看泌尿科比较好Its not really his day, is it?今天真是诸事不顺 不是吗Some young leopards grow up to be brilliant opportunists.一些小猎豹将成长为杰出的投机捕猎者But even they find life hard here in the Kalahari.但连他们都觉得在喀拉哈里生存很艰难These bizarre little birds are baby ostriches.那些古怪的小鸟是鸵鸟雏鸟Theyre just a few days old.他们才刚出生几天In time, theyll become superb desert survivors.假以时日 他们会成为杰出的沙漠行者But in the Kalahari, these early days are perilous.但在喀拉哈里 雏鸟期面临着诸多危险Like leopards and meerkats,如同猎豹和狐獴一样adult ostriches成年鸵鸟can extract all the moisture they require from their food.能够从食物中汲取所需的水分The chicks, however,然而 雏鸟wont survive much more than another day without water.缺了水几乎一天都活不下去But theres none in sight.但目之所及都没有水How can their parents conjure up water out here?他们的父母要怎么变出水来呢201311/266691 襄阳襄城区妇幼保健院中医院看妇科好不好襄阳中医医院四维彩超预约




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