19 Hot and Cold

CHAPTER NINETEEN HOT AND COLD Chemical bond (noun). This is the force that holds two atoms together. There are different kinds of bonds, and they can be broken and reformed. Think of it like a bunch of kids holding hands playing Red Rover. They let go of each other's hands and sometimes find new partners. WHEN BIRDIE AND I WALKED INTO MY HOUSE, it was oddly quiet. No loud screaming or thundering feet of twenty kindergartners slamming into furniture. "They must be eating," I said as we headed into the kitchen. Sure enough, Liam sat with his friends at a long folding metal table draped in a tablecloth dotted with planets. The boys and girls were finishing up their lunch, which were little pizza bagels that looked like flying saucers. There were also slices of lunchmeat cut into the shape of crescent moons and stars. "Hi!" I said. "I'm back!" "Yay!" cried a bunch of kids. A girl with two small pigtails shouted, "Spin me, Kate!" "And me!" cried Liam.

第十九章冷热化学键（名词）。 这是把两个原子结合在一起的力。 化学键有不同的种类，它们可以被打破，也可以被重组。 把它想象成一群孩子手牵着手玩《红色漫游者》。 他们放开彼此的手，有时会找到新的伴侣。 当我和伯蒂走进我的房子时，屋里出奇地安静。 没有大声的尖叫，也没有20个幼儿园孩子撞家具的雷鸣般的脚步声。 “他们一定在吃东西，”我们走进厨房时，我说。 果然，利亚姆和他的朋友们坐在一张长长的折叠金属桌子旁，桌子上铺着点缀着行星的桌布。 男孩和女孩们正在吃完他们的午餐，那是看起来像飞碟的小披萨百吉饼。 还有切成新月和星星形状的午餐肉片。 “嗨!”我说。“我回来了!”“耶！”一群孩子叫道。 一个扎着两条小辫子的女孩喊道：“给我转，凯特！”“还有我！”利亚姆叫道。

"Well, not right now," said Dad, who was by the fridge filling up a pitcher with more water. "Since you all need to finish your lunch so we can eat ice cream cake." "Cake!" Liam cried, and my heart sank. "Cake! Cake! Cake!" the rest of the kids chanted along with him. I looked at Birdie, and she looked at me. "I can't wait to see this masterpiece," said Mom, who was wearing a SPACE CREW T-shirt just like me and Dad. I bit my bottom lip. "Well, about that. You will see the cake. But just a little later." Then I explained how I had just missed Mr. Arvanites and that we could pick up the cake before dinner. "No ice cream cake for my party?" asked Liam, his voice wobbling. He blinked, and I was afraid he would start to cry. "Actually, you will still have ice cream. But it won't be a cake. Instead, you will have... astronaut ice cream," I announced. A bunch of kids, and my parents, stared at me in amazement and confusion.

“好吧，现在不行，”爸爸说，他正在冰箱旁往水罐里灌水。 “因为你们都要吃完午饭，这样我们才能吃冰淇淋蛋糕。” “蛋糕!”利亚姆哭了，我的心一沉。 “蛋糕!蛋糕!蛋糕！”其他的孩子也跟着喊。 我看着伯迪，她也看着我。 “我迫不及待地想看看这个杰作，”妈妈说，她和我和爸爸一样穿着一件SPACE CREW的t恤。 我咬着自己的下嘴唇。“好吧，关于这一点。 你会看到蛋糕的。不过要晚一点。” 然后我解释说，我刚刚错过了阿尔万尼斯先生，我们可以在晚饭前把蛋糕取走。 “我的派对没有冰淇淋蛋糕吗？”利亚姆问道，他的声音颤抖着。 他眨了眨眼睛，我担心他会哭起来。 “实际上，你还是会吃冰淇淋的。 但它不会是蛋糕。相反，你会…… 宇航员冰淇淋，”我宣布。 一群孩子，还有我的父母，惊讶而困惑地盯着我。

"Using some awesome chemistry skills," I said in my most enthusiastic voice, "we're going to make futuristic astronaut ice cream. With liquid nitrogen." There was silence, and then suddenly the room erupted into cheers. My mom raised her eyebrows in concern. "Kate, are you really sure about this?" "She did make ice cream last year for her project," said Dad. "Oh, I'm very sure," I said. "Let's get ready. Because it's time for the coolest ice cream ever!" "At least we've done this one before," said Dad. "I'll go grab the liquid nitrogen from the garage. Operation Make the Atmosphere of Jupiter was a huge success, and we have plenty of liquid nitrogen left over." "See?" whispered Birdie. "It's all working out." "It is," I agreed. Soon enough Dad, wearing his safety goggles and gloves, came back with the dewar of liquid nitrogen. A dewar is an awesome vacuum-insulated container that keeps the liquid nitrogen nice and cold so that it doesn't boil away. "So, everyone, nitrogen is usually a gas," I explained, "but when it's chilled under high pressure, it becomes a cold liquid. And when I say 'cold,' I mean arctic cold. That's why we need to be super safe."

“利用一些了不起的化学技术，”我用最热情的声音说，“我们将制作出未来派的宇航员冰淇淋。 用液氮。”一阵沉默，然后房间里突然爆发出欢呼声。 我妈妈担心地扬起眉毛。 “凯特，你真的确定吗？”爸爸说：“她去年的作业是做冰淇淋的。” “哦，我很确定，”我说。 “让我们准备好。因为是时候推出有史以来最酷的冰淇淋了！”“至少我们以前做过这个，”爸爸说。 “我去车库里拿液氮。 创造木星大气层的行动取得了巨大的成功，我们还剩下了大量的液氮。” “看到了吗？”小鸟小声说。“一切都解决了。” “是的，”我表示同意。很快，爸爸戴着护目镜和手套，拿着液氮瓶回来了。 杜瓦瓶是一种很棒的真空隔热容器，可以保持液氮的低温，使其不会沸腾。 “那么，各位，氮气通常是一种气体，”我解释说，“但是当它在高压下冷却时，它就变成了一种冷液体。 当我说“冷”的时候，我指的是北极的寒冷。 这就是为什么我们需要超级安全。”

"With these." Dad pointed to the safety goggles he was wearing with one of his blue cryogenic gloves. Those are special gloves that scientists wear to protect their hands from extreme temperatures. "It's important to be careful since the liquid nitrogen is negative one hundred and ninety-six degrees Celsius," said Mom, who helped me grab ingredients for the ice cream: whole milk, sugar, salt, chocolate syrup, mint extract, and vanilla. Plus mixing bowls, measuring cups, and spoons. "So nobody can touch that dewar of liquid nitrogen," added Mom. "Not even us," I added as I ran to grab goggles and gloves from the basement. Birdie was already retrieving our matching blue lab coats from the mud room. After putting on my safety equipment, I set the two mixing bowls on the counter, one for me, one for Birdie. I also pre-measured out one cup of sugar for each of us. Luckily, we had two sets of measuring cups. "It's going to be incredible," gushed Birdie. "Wait till you astronauts taste all of the little crunchy shapes." "I scream, you scream, we all scream for ice cream," shouted Dad.

“这些”。爸爸指着他戴着的护目镜和他的一只蓝色低温手套。 这些是科学家戴上的特殊手套，用来保护他们的手免受极端温度的伤害。 “一定要小心，因为液氮的温度是零下196摄氏度，”妈妈说，她帮我拿了冰淇淋的原料：全脂牛奶、糖、盐、巧克力糖浆、薄荷提取物和香草。 再加上搅拌碗、量杯和勺子。 “所以没人能碰液氮杜瓦瓶，”妈妈补充说。 “连我们都没有，”我一边跑去地下室拿护目镜和手套一边补充道。 伯迪已经从泥房拿回了我们的蓝色实验服。 穿上安全装备后，我把两个搅拌碗放在柜台上，一个给我，一个给小鸟。 我还给我们每人提前量好了一杯糖。 幸运的是，我们有两套量杯。 “这将是不可思议的，”伯迪滔滔不绝地说。 “等着你们宇航员尝尝所有这些脆脆的形状吧。” “我尖叫，你尖叫，我们都为冰淇淋尖叫，”爸爸喊道。

The kids all started screaming, with Liam yelling the loudest. "Thanks, Dad," I joked. Putting my fingers to my lips, I motioned for them to be quiet. The hollering and cheering continued. "No ice cream until you're quiet," said Birdie. Suddenly, there was silence. Mom gave Birdie a thumbs-up. "You could become a principal someday if you wanted," she said. "Okay, everyone, we're going to have some fun with chemistry," I announced. "All of you are about to eat astronaut ice cream." I turned to Dad and Birdie. "You guys ready?" "Oh yeah," said Birdie, who, just like me, stood in front of giant blue mixing bowls. "First thing we need to do is add the sugar," I said, and both Birdie and I dumped our sugar into our bowls. Next we added in two tablespoons of vanilla. "This will spike it with flavor," I said. Birdie bent down and smelled her mixture. "Mmmm, yummy." I held up mint extract. "In mine, I'm squirting one teaspoon of mint extract. So we'll have options. Vanilla and mint astronaut ice cream." And then I grabbed the carton of salt. "Where's our birthday boy?"

孩子们都开始尖叫，利亚姆叫得最大。 “谢谢，爸爸，”我开玩笑说。我把手指放在嘴唇上，示意他们安静下来。 喊声和欢呼继续着。 “在你安静下来之前不要吃冰淇淋，”小鸟说。 突然，一片寂静。 妈妈朝小鸟竖起大拇指。 “如果你愿意，有一天你可以成为校长，”她说。 “好了，各位，我们将在化学上找点乐子。”我宣布。 “你们所有人都要吃宇航员冰淇淋了。” 我转向爸爸和小鸟。 “你们准备好了吗？”“哦，是的，”小鸟说，她和我一样，站在巨大的蓝色搅拌碗前。 “我们要做的第一件事就是加糖，”我说，我和伯蒂都把糖倒进了碗里。 接下来我们加入两汤匙香草。 “这将使它的味道更浓，”我说。 小鸟弯下腰闻了闻她的混合物。 “嗯,好吃。”我拿起薄荷精。 “我喷的是一茶匙薄荷提取物。 所以我们有选择。香草薄荷宇航员冰淇淋。” 然后我抓起那盒盐。 “我们的寿星在哪里？”

Liam jumped up. "I'm here!" I poured some salt into my cupped hand. "Take a pinch, Liam, and toss some into both bowls." Liam dramatically pinched his fingers together. "I'm a space lobster!" he cried. "Just don't be a greedy lobster. Then you'll be shellfish," Birdie joked. After I stopped giggling, I explained to everyone why you needed to add salt. "It lowers the freezing point," I said. "That allows the milk mixture to get nice and cold without freezing, which is what we need for ice cream. Right now, I want everyone to make a giant whoop if you are ready to get started." "Whoop whoop!" the kids cried. "And now we're going to add a third of a gallon of whole milk. It has to be whole milk. None of that low-fat stuff." I made a silly face as Mom handed me the gallon of whole milk and I poured a third of a gallon into each bowl. "We need the fat to give the ice cream its creamy texture. Otherwise, the sugar-milk mixture would turn into a giant iceberg when it interacts with the liquid nitrogen." "Can we eat the ice cream now?" lisped a girl with one missing front tooth. "Almost! We need to get all of the ingredients mixed together and then add the liquid nitrogen so our

利亚姆跳了起来。“我在这里!”我把一些盐倒在我的杯中。 “拿一点，利亚姆，在两个碗里都撒一点。” 利亚姆戏剧性地把手指捏在一起。 “我是一只太空龙虾！” “不要做一只贪婪的龙虾。 然后你就会变成贝类，”小鸟开玩笑说。 在我停止咯咯笑之后，我向每个人解释为什么你需要加盐。 “它能降低冰点，”我说。 “这使得牛奶混合物在不冻结的情况下变得又好又冷，这正是我们制作冰淇淋所需要的。” 现在，如果你准备好开始了，我希望每个人都发出巨大的欢呼声。” “嗬嗬嗬！”孩子们叫道。 “现在我们要加入三分之一加仑的全脂牛奶。 必须是全脂牛奶。不要吃低脂的东西。” 当妈妈递给我一加仑全脂牛奶时，我做了个鬼脸，我把三分之一加仑的牛奶倒进每个碗里。 “我们需要脂肪赋予冰淇淋奶油般的口感。 否则，糖牛奶混合物在与液氮相互作用时会变成一个巨大的冰山。” “我们现在可以吃冰淇淋了吗？”一个缺了一颗门牙的女孩口齿不清地说。 “差不多了!我们需要把所有的原料混合在一起然后加入液氮，这样我们