Chapter 3-20110308专用课件.ppt

In contrast, when sodium is exposed to chlorine gas, a compound, sodium chloride, is formed; the two elements lose their chemical identity. 相反，当钠暴露于氯气中时，就会形成一种化合物氯化钠；这两种元素都失去了它们各自的化学特性。 There are two types of mixtures. Homogeneous or uniform mixture, in which, the composition of the mixture is the same throughout. 混合物有两种。均匀混合物中各组分都是均匀的。 Another name for a homogeneous mixture is a solution. A solution is made up of a solvent, the substance present in largest amount, and one or more solutes. 均匀混合物的另一个名称叫做溶液。溶液由占有最大数量的物质溶剂和一种或多种溶质组成。 Solution:[s?’lu:??n] n. 溶液 Solvent:[‘s?lv?nt] n. 溶剂 Solute: [‘s?lju:t] n. 溶解物,溶质 Most commonly, the solvent is a liquid, while solutes may be solids, liquids, or gases. Soda water is solution of carbon dioxide (solute) in water (solvent). 最常见的溶剂是液体，而溶质可以是固体、液体或气体。苏打水就是二氧化碳（溶质）溶于水（溶剂）中形成的溶液。 Soda: [‘s?ud?] n. 苏打, 碱 * Chapter 3 Matter, Element, Compound and Mixture If you’re planning to be an engineer, you can be sure that many of the materials you will work with have been synthesized by chemists. Some of these materials are organic (carbon-containing). 如果你计划成为一名工程师，你可以确定你将要打交道的很多材料都是化学家们合成的。这些材料有些是有机的（含碳的）。 They could be familiar plastics like polyethylene or the more esoteric plastics used in unbreakable windows and nonflammable clothing. Other materials, including metal alloys, semiconductors, and superconductors, are inorganic in nature. 它们可能是像常见的聚乙烯塑料或是用于不易碎窗户和阻燃衣服的更神秘的塑料。其它材料，包括金属合金、半导体以及超导体，本质上都是无机的。 Polyethylene: [,p?li’eθili:n] n. 聚乙烯 Esoteric: [,es?u’terik] adj. 机密的; 神秘的; 难解的 Nonflammable:[,n?n’fl?m?bl] adj. 不燃烧的 Alloy: [‘?l?i] n. 合金 Perhaps you are a health science major, looking forward to a career in medicine or pharmacy. If so, you will want to become familiar with the properties of aqueous solutions, which include blood and other body fluids. 也许你主修保健科学，希望从事一个医学或药学方面的工作。如果这样，你将希望熟悉水溶液的性质，包括血液和其它体液。 Pharmacy:[‘fɑ:m?si] n.药房，药剂学，制药业 Aqueous: [‘eikwi?s] adj. 水的,水性的 Chemists have made many life-saving products over the past few d