2.14 化学变化
Section outline
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Do you like to cook?
::你喜欢做饭吗?Cooking is a valuable skill that everyone should have. Whether it is fixing a simple grilled cheese sandwich or preparing an elaborate meal, cooking demonstrates some basic ideas in chemistry . When you bake bread, you mix some flour, sugar, yeast, and water together. After baking, this has been changed to form bread, another substance that has different characteristics and qualities from the original materials. The process of baking has produced chemical changes in the ingredients that result in bread being made.
::烹饪是每个人都应该拥有的宝贵技能。 无论它正在修一个简单的烤奶酪三明治,还是准备一个精心准备的饭,烹饪都展示了一些化学方面的基本想法。当你烤面包时,你将一些面粉、糖、酵母和水混合在一起。烘烤后,这已经变成了面包,与原始材料有不同特性和品质的另一种物质。烘烤过程在成分中产生了化学变化,导致面包的制作。Chemical Change
::化学化学变化Most of the we know about do not exist freely in nature. Sodium cannot be found by itself (unless we prepare it in the laboratory) because it interacts easily with other materials. On the other hand, the element helium does not interact with other elements to any extent. We can isolate helium from natural during the process of drilling for oil.
::我们所知道的多数并非自由存在的。 钠本身无法找到( 除非我们在实验室中准备) , 因为它很容易与其他材料发生相互作用。 另一方面, 元素氦与其他元素之间没有任何程度的相互作用。 我们可以在石油钻探过程中将从天然分离出来 。A chemical change produces a different materials than the ones we started with. One aspect of the science of chemistry is the study of the changes that matter undergoes. If all we had were the elements and they did nothing, life would be very boring (in fact, life would not exist since the elements are what make up our bodies and sustain us). But the processes of change that take place when different chemicals are combined produce all the materials that we use daily.
::化学变化产生的材料与我们最初的材料不同。化学科学的一个方面是研究所经历的变化。 如果我们只有这些元素,它们却无所作为,那么生命将是非常无聊的(事实上,生命将不存在,因为这些元素构成我们的身体并支撑着我们 ) 。 但是,当不同的化学物质被合并在一起时,变化的过程会产生我们每天使用的所有材料。One type of chemical change (already mentioned) is when two elements combine to form a . Another type involves the breakdown of a compound to produce the elements that make it up. If we pass an electric current through bauxite (aluminum oxide, the raw material for aluminum metal), we get metallic aluminum as a product.
::一种化学变化(已经提到过)是当两个元素合并成一个。另一种是化合物的分解以产生组成它的元素。如果我们通过铝土(氧化铝,铝金属的原材料)输送电流,我们就会获得金属铝产品。Electrolytic production of aluminum. However, the vast majority of chemical changes involve one compound being transformed into another compound. There are literally millions of possibilities when we take this approach to chemical change. New compounds can be made to produce better fabrics that are easier to clean and maintain; they can help preserve food so it doesn’t spoil as quickly; we can make new medicines to treat diseases; even products, such as airbags (as seen in the simulation below), use a chemical change to improve the world around us.
::然而,绝大多数化学变化都涉及一种化合物被转化成另一种化合物。 当我们采取这种方法来改变化学成分时,实际上有数百万种可能性。 新的化合物可以制造出更干净、更便于清洁和维护的更佳布料;它们可以帮助保存食物,这样它不会迅速变坏;我们可以制造新的药物来治疗疾病;甚至气囊等产品(见下文的模拟)也可以使用化学变化来改善我们周围的世界。Summary
::摘要-
A chemical change produces different materials than the ones we started with.
::化学变化产生的材料 与我们开始的材料不同。
Review
::回顾-
What is a chemical change?
::什么是化学变化? -
List three types of chemical changes.
::列出三种化学变化。
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A chemical change produces different materials than the ones we started with.
