化学专业英语翻译(共7页).doc

《化学专业英语翻译(共7页).doc》由会员分享，可在线阅读，更多相关《化学专业英语翻译(共7页).doc（7页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、精选优质文档-倾情为你奉上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

2、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 molecules 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

3、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

4、liquid (Br2) and a solid (I2) whose vapor pressures also indicate small intermolecular forces. Certain properties 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 m

5、embers 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. T

6、he larger atomic 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

7、 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, but 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

8、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 am

9、orphous form. Rhombic sulfur is obtained by crystallization from a suitable solution, such as CS2, and it melts at 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

10、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 fr

11、om its container. 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

12、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 liquid sulfur is quenched by pouring it into cold water, the amorphous form of sulfur i

13、s 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 rhomb

14、ic 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

15、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

16、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, althoug

17、h in previous years much of this SO2 was discarded through exceptionally tall smokestacks. Fortunately, it is now economically favorable to recover these gases, thus greatly reducing this type of atmospheric pollution. A typical roasting reaction involves the change:硫的形式，二氧化硫在焙烧硫化矿回收和转化为硫酸，虽然以前这种二氧化

18、硫被丢弃通过高大的烟囱。幸运的是，现在是经济上有利的回收这些气体，从而大大减少这种类型的大气污染。一个典型的焙烧反应涉及改变：Phosphorus, below 800 consists of tetratomic molecules, P4. Its molecular structure provides for a covalence of three, as may be expected from the three unpaired p electrons in its atomic structure, and each atom is attached to three oth

19、ers6. Instead of a strictly orthogonal orientation, with the three bonds 90 to each other, the bond angles are only 60. This supposedly strained structure is stabilized by the mutual interaction of the four atoms (each atom is bonded to the other three), but it is chemically the most active form of

20、phosphorus. This form of phosphorus, the white modification, is spontaneously combustible in air. When heated to 260C it changes to red phosphorus, whose structure is obscure. Red phosphorus is stable in air but, like all forms of phosphorus, it should be handled carefully because of its tendency to

21、 migrate to the bones when ingested, resulting in serious physiological damage.磷，低于800由四原子分子，P。其分子结构提供了一个共价键的三，可预期从三个未配对的电子的原子结构，每个原子连接到三others6。而不是一个严格正交的方向，与三个债券90对方，债券的角度只有60。这种紧张的结构是稳定的相互交流的四个原子（每个原子保税其他三），但它是最活跃的形式磷化学。这种形式的磷，白色的修改，是在空气中自燃。当加热到260摄氏它变红，磷，其结构是模糊的。红色磷在空气中稳定，如各种形式的磷，它应该谨慎处理，因为它的趋势，

22、迁移到骨头，当摄入，造成严重的生理损害。Elemental carbon exists in one of two crystalline structures diamond and graphite. The diamond structure, based on tetrahedral bonding of hybridized sp3 orbitals, is encountered among Group IV elements. We may expect that as the bond length increases, the hardness of the diamond-

23、type crystal decreases. Although the tetrahedral structure persists among the elements in this group carbon, silicon, germanium, and gray tin the interatomic distances increase from 1.54 A for carbon to 2.80 A for gray tin. Consequently .the bond strengths among the four elements range from very str

24、ong to quite weak. In fact, gray tin is so soft that it exists in the form of microcrystals or merely as a powder. Typical of the Group IV diamond-type crystalline elements, it is a nonconductor and shows other nonmetallic properties7.碳元素存在于一个2-金刚石和石墨的晶体结构。金刚石结构，基于四面体键杂化轨道中遇到的改变，族元素。我们可以预期，随着债券长度的增加，硬度的菱形晶体减少。虽然四面体结构之间存在的元素在这一组碳，硅，锗，锡和灰色的原子间的距离从1.54增加一个碳2.80的灰锡。因此。债券的优势四个元素之间的范围从非常强，很弱。事实上，灰锡很软，它存在的形式，微晶或仅仅作为一种粉。典型的四组菱形晶体元件，它是一个非导体和其他非金属properties7显示。专心-专注-专业