化学专业英语翻译2

1、02. THE NONMETAL ELEMENTSWe noted earlier. that -nonmetals exhibit properties that are greatly different from those of the metals. As a rule, the nonmetals are poor conductors of electricity (graphitic carbon is an exception) and heat; they are brittle, are often intensely colored, and show an unusually wide range of melting and boiling points. Their molecular structures, usually involving ordinary covalent bonds, vary from the simple diatomic molecules of H2, Cl2, I2, and N2 to the giant molecu

2、les of diamond, silicon and boron. 我们前面提到的。-非金属表现出的性质有很大的不同，这些金属。作为一项规则，非金属都是热的不良导体电（石墨碳是个例外）和热；他们是脆的，往往是强烈的色彩，并显示一个非常广泛的熔点和沸点。其分子结构，通常涉及一般共价键，从简单的双原子分子氢，氯，碘，和氮气的大分子的金刚石，硅和硼。 The nonmetals that are gases at room temperature are the low-molecular weight diatomic molecules and the noble gases that exert very small intermolecular forces. As the molecular weight increases, we encounter a liquid (Br2) and a solid (I2) whose vapor pressures also indicate small intermolecular forces. Certain properties

3、 of a few nonmetals are listed in Table 2非金属，在室温下是气体的分子量和双原子分子的惰性气体，施加很小的分子间力。随着分子量增大，我们遇到一个液体（溴）和固体（碘）的蒸气压力也表明小分子间力。某些性能的几个非列于表2 Simple diatomic molecules are not formed by the heavier members of Groups V and VI at ordinary conditions. This is in direct contrast to the first members of these groups, N2 and O2. The difference arises because of the lower stability of bonds formed from p orbitals of the third and higher main energy levels as opposed to the second main energy level2. The larger ato

4、mic radii and more dense electron clouds of elements of the third period and higher do not allow good parallel overlap of p orbitals necessary for a strong bond. This is a general phenomenon strong bonds are formed only between elements of the second period. Thus, elemental nitrogen and oxygen form stable molecules with both and bonds, but other members of their groups form more stable structures based on bonds only at ordinary conditions. Note3 that Group VII elements form diatomic molecules, b

5、ut bonds are not required for saturation of valence.简单的双原子分子没有形成较重的群体成员的第五和第六在普通条件。这是在直接对比的第一个成员的这些群体，氮气和氧气。差异是因为较低的稳定的债券形成轨道的第三个及以上的主要能量水平相对于第二主要能源。较大的原子半径和更密集的电子云的第三周期元素和较高的不允许平行重叠的轨道需要一个强大的债券。这是一个普遍现象的债券形成的唯一的元素之间的二期。因此，氮元素和氧形成稳定的分子与和债券，但其他成员的团体形成更稳定的结构的基础上债券只在普通条件。注3，第七族元素形成双原子分子，但债券不需要饱和价。 Sulfur exhibits allotropic forms. Solid sulfur exists in two crystalline forms and in an amorphous form. Rhombic sulfur is obtained by crystallization from a suitable solution, such as CS2, and it melts a

6、t 112C. Monoclinic sulfur is formed by cooling melted sulfur and it melts at 119C. Both forms of crystalline sulfur melt into S-gamma, which is composed of S8 molecules. The S8 molecules are puckered rings and survive heating to about 160C. Above 160C, the S8 rings break open, and some of these fragments combine with each other to form a highly viscous mixture of irregularly shaped coils. At a range of higher temperatures the liquid sulfur becomes so viscous that it will not pour from its contai

7、ner. The color also changes from straw yellow at sulfurs melting point to a deep reddish-brown as it becomes more viscous.硫展品同素异形体。固硫存在2晶体形式和非晶态形式。正交硫是通过结晶从一个合适的解决方案，如二硫化碳，它融化在112摄氏单斜硫是由冷却熔化的硫和它融化在119C两种形式的结晶硫磺熔化成s-gamma，由8分子。级分子折叠环和生存加热至约160C .160以上，级环打开，其中一些片段相互结合，形成高粘度混合物的不规则形线圈。在一系列的温度较高的液体硫成为粘性，它不会从容器。颜色的变化也从稻草黄色硫的熔点为深褐色因为它变得更加粘稠。As4 the boiling point of 444 C is approached, the large-coiled molecules of sulfur are partially degraded and the liquid sulfur decreases in viscosity. If the hot

8、liquid sulfur is quenched by pouring it into cold water, the amorphous form of sulfur is produced. The structure of amorphous sulfur consists of large-coiled helices with eight sulfur atoms to each turn of the helix; the overall nature of amorphous sulfur is described as3 rubbery because it stretches much like ordinary rubber. In a few hours the amorphous sulfur reverts to small rhombic crystals and its rubbery property disappears.4沸点444接近，large-coiled分子的硫部分退化和液体的粘度降低。如果把热的液体硫到入冷水中淬火，产生无定形硫。无定形硫

9、的结构由八个硫原子的large-coiled螺旋与螺旋的每一圈；整体性描述一个无定形硫橡胶因为它像普通橡胶。在几个小时无定形硫还原为小菱形晶体和它的弹性也会消失。Sulfur, an important raw material in industrial chemistry, occurs as the free element, as SO2 in volcanic regions, as H2S in mineral waters, and in a variety of sulfide ores such as iron pyrite FeS2, zinc blende ZnS, galena PbS and such, and in common formations of gypsum CaSO4 2H2O, anhydrite CaSO4, and barytes BaSO4 2H2O. Sulfur, in one form or another, is used in large quantities for making sulfuric acid, fertilizers, insecticides, and paper.硫，一个重要的原材料工业化学，是自由的元素，如二氧化硫在火山地区，如硫化氢矿泉水，并在各种硫化矿如铁黄铁矿，闪锌矿，方铅矿等，并在共同形成石膏CaSO 42 H2O，硬石膏CaSO 4，和重晶石BaSO2 H2O。硫，一种或另一种形式，被大量用于制造硫酸，化肥，杀虫剂，和纸。Sulfur in the form of SO2 obtained in the roasting of sulfide ores is recovered and converted to sulfuric acid, although in previous years much of this SO2 was discarded through exceptionally tall smokestacks. Fortunately, it is now economically favo

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