化学专业英语(修订版)翻译

1、.01 THE ELEMENTS AND THE PERIODIC TABLE1 元素和元素周期表The number of protons in the nucleus of an atom is referred to as the atomic number, or proton number, Z. The number of electrons in an electrically neutral atom is also equal tothe atomic number, Z. The total mass of an atom is determined very nearly

2、 by the total number of protons and neutrons in its nucleus. This total is called the mass number, A. The number of neutrons in an atom, the neutron number, is given by the quantity A-Z.在一个原子核中的质子数量被称为原子序数，或质子数，Z 。在一个电中性原子中的电子数量也等于原子序数，Z 。一个原子的总质量被测定是非常接近于原子核中质子和中子的总数。这个总数被称为质量数，A。在一个原子中的中子数量等于A Z 的

3、数量。The term element refers to, a pure substance with atoms all of a single kind. To the chemist the "kind" of atom is specified by its atomic number, since this is the property that determines its chemical behavior. At present all the atoms from Z = 1 to Z = 107 areknown; there are 107 che

4、mical elements. Each chemical element has been given a name and a distinctive symbol. For most elements the symbol is simply the abbreviated form ofthe English name consisting of one or two letters, for example:这个术语 (指 chemical element)也可以指由相同质子数的原子组成的纯化学物质。对化学家来说，这类原子通过原子数来说明，因为它的性质是决定其化学行为。目前，从Z=1

5、到Z= 107 的所有原子是知道的； 有 107 种化学元素。 每一种化学元素起了一个名字和独特的象征。对于大多数元素都仅仅是一个象征的英文名称缩写形式，由一个或两个字母组成， 例如： oxygen=O nitrogen = N neon=Ne magnesium = Mg氧 = =O 氮 = = N 氖 = = Ne 镁 = =Mg.Someelements,whichhavebeenknownfor a longtime,havesymbolsbasedon theirLatin names, for example:很久以来就已经知道一些元素，根据他们的拉丁名字符号命名，例如：iron=

6、Fe(ferrum) copper=Cu(cuprum) lead=Pb(plumbum)铁= =铁(铁)铜= =铜(铜)铅= =铅(铅)A complete listing of the elements may be found in Table 1.一个完整的元素可以在表1 中被发现。Beginning in the late seventeenth century with the work of Robert Boyle, who proposedthe presently accepted concept of an element, numerous investigations

7、 produced a considerable knowledge of the properties of elements and their compounds1. In 1869, D.Mendeleev and L. Meyer, working independently, proposed the periodic law. In modernform, the law states that the properties of the elements are periodic functions of their atomic numbers. In other words

8、, when the elements are listed in order of increasing atomic number, elements having closely similar properties will fall at definite intervalsalong the list. Thus it is possible to arrange the list of elements in tabular form with elements having similar properties placed in vertical columns2. Such

9、 an arrangement is called a periodic.早在十七世纪末期，罗伯特波义耳就开始了这项工作，他提出了现在公认的元素的概念，大量的研究使我们对元素及其化合物的性质有了相当的了解。在1869 年，门捷列夫和迈耶，独立工作， 提出了元素周期律。用现代方式， 元素周期律阐述了元素的特性原子序数的周期性函数。 换句话说， 当按原子序数增加的顺序排列元素，具有相近特性的元素将沿着列表以一定的间隔下降。因此， 将具有类似性质的元素排成纵列，从而把元素排成表格形式是有可能的。像这样的排列叫元素周期表。.Each horizontal row of elements constit

10、utes a period. It should be noted that the lengths of the periods vary. There is a very short period containing only 2 elements, followed by two short periods of 8 elements each, and then two long periods of 18 elements each. The next period includes 32 elements, and the last period is apparently in

11、complete. With thisarrangement, elements in the same vertical columnhave similar characteristics. Thesecolumns constitute the chemical families or groups. The groups headed by the members of the two 8-element periods are designated as main group elements, and the members of the other groups are call

12、ed transition or inner transition elements.每个水平排的元素构成一个周期。 但应该注意的是， 周期长度会发生改变。 非常短的周期只包含二元素，后面跟着两个 8 个元素短周期，然后是两个由 18个元素组成的长周期。下一个周期包括 32 个元素，最后一个周期明显是不完整的。按照这样的安排，在同一垂直栏的元素有相似的特点。这些垂直栏构成化学族。两个8 个元素的周期组成的元素被认为是主族元素，其他族的元素被称为过渡元素。In the periodic table, a heavy stepped line divides the elements into m

13、etals and nonmetals. Elements to the left of this line (with the exception of hydrogen) are metals, while those to the right are nonmetals. This division is for convenience only; elements bordering the linethe metalloids-have properties characteristic of - both metals and nonmetals. It may be seen t

14、hat most of the elements, including all the transition and inner transition elements, are metals.在元素周期表，阶梯线将元素分成金属和非金属元素等。阶梯线左边的元素(除氢 )是金属，右边的是非金属元素等。这个分割仅为方便使用；元素分界线上的元素 准金属具有金属和非金属的特性。这可以看出，大部分的元素，包括所有的过渡和内在过渡元素，是金属。Except for hydrogen, a gas, the elements of group IA make up the alkali metal fami

15、ly. Theyare veryreactivemetals,andtheyare neverfoundin the elementalstatein nature.However,their compoundsare widespread. Allthemembersofthealkali metalfamily,form ionshaving a chargeof 1+ only. In contrast,the elementsofgroup IB copper,silver, and gold are comparatively inert. They are similar to t

16、he alkali metals in that theyexist as 1+ ions in manyof their compounds.However, asischaracteristicof mosttransition elements, they form ions having other charges as well.除了氢气， IA 由碱金属元素组成。他们是非常活泼的金属，在自然界中，它们从没有以元素态形式出现。然而，他们的化合物是广泛存在的。所有的碱金属离子仅有1+ 的电荷。相比之下， IB 铜，银和金是惰性的。在他们的许多化合物他们存在1+ 离子，这与碱金属离子是相

17、似的。然而，像许多过渡元素所具有的特点一样，他们也形成具有其他电荷的离子。The elementsof groupIIA are knownas the alkalineearth metals.Their characteristicionic chargeis 2+. Thesemetals,particularlythe last two membersof the group,arealmostas reactiveas the alkalimetals.The groupIIB elements zinc,cadmium,andmercury are less reactive th

18、an are those of group II A5, but are more reactive than the neighboring elements of group IB. The characteristic charge on their ions is also 2+.IIA 的元素被称为碱土金属。其特点是离子电荷2+ 。这些金属，特别是最后两个元素，几乎具有与碱金属一样的反应活性。IIB 元素，锌，镉，汞比IIA 的元素具有更少的反应活性，但是比相邻的IB 的元素有更强的反应活性。IB 的元素离子的特征电荷也是2+ 。With the exception of boron

19、, group IIIA elements are also fairly reactive metals. Aluminum appears to be inert toward reaction with air, but this behavior stems from the fact that the metal forms a thin, invisible film of aluminum oxide on the surface, which protects the bulk of the metal from further oxidation. The metals of

20、 group IIIA form ions of 3+ charge. GroupIIIB consists of the metals scandium, yttrium, lanthanum, and actinium.除了硼、 IIIA 元素也是具有相当强活性金属。在空气中铝似乎惰性的，但这种行为的根源是.金属表面形成了一层薄的、不可见的氧化铝膜，这层膜保护大量的金属的进一步氧化。IIIA金属离子具有 3+ 的电荷。 IIIA 由金属钪，钇，镧系和锕系元素组成。Group IVA consists of a nonmetal, carbon, two metalloids, silico

21、n and germanium, and two metals, tin and lead. Each of these elements forms some compounds with formulas which indicate that four other atoms are present per group IVA atom, as, for example, carbontetrachloride,CCl4.ThegroupIVB metals titanium,zirconium,andhafnium alsoforms compounds in which each g

22、roup IVB atom is combined with four other atoms; thesecompounds are nonelectrolytes when pure.IVA 元素由一个非金属，碳、两个准金属，硅和锗，和两个金属，锡和铅组成。按照配位规则，这些元素的每一种形成一些化学物，这表明每一个IVA 原子需要四个其他原子配位，例如，四氯化碳CCl4 。 IVB 金属 钛、锆、和铪 也形成化合物，其中每个IVB 原子结合四个其他原子；这些化合物的纯物质是非电解质。The elements of group V A include three nonmetals nitr

23、ogen, phosphorus, and arsenic and two metals antimony and bismuth. Although compounds with the formulas N2O5, PCl5, and AsCl5 exist, none of them is ionic. These elements do formcompounds-nitrides,phosphides,andarsenidesin whichionshavingchargesofminus three occur. The elements of group VB are all m

24、etals. These elements form such avariety of different compounds that their characteristics are not easily generalized.VA 元素包括三种非金属-氮、磷、砷，和两种金属锑和铋。尽管物质N2O5， PCl 5 ， AsCl 5存在， 但是其中没有一个是离子。这些元素能形成化合物 氮化物，磷化物，和砷化物 其中离子带 3- 价的负电荷。 VB 的元素都是金属。这些元素形成各种不同的化合物，它们的特性不容易归纳。With the exception of polonium, the e

25、lements of group VIA are typical nonmetals. They are.sometimes known, as the, chalcogens, from the Greek word meaning "ash formers". Intheir binary compounds with metals they exist as ions having a charge of 2-. The elementsof group A are all nonmetalsandare knownas the halogens.from the G

26、reektermmeaning"salt formers.” Theyare the mostreactivenonmetalsandare capableofreacting with practically all the metals and with most nonmetals, including each other.除了钋的元素， VIA 族元素是典型的非金属。他们是众所周知的硫族元素，这来自于希腊字母，词意是“灰的创造者”。在他们与金属离子形成的二元化合物中离子带2- 价的电荷。A 族的元素都是非金属，被称为卤素，来自希腊术语，意即“盐的创造者”。他们是最具有反应活

27、性的非金属，能够与所有的金属和大多数非金属反应，包括互相之间的反应。The elements of groups B, B, and VIIIB are all metals. They form such a wide Varietyof compounds that it is not practical at this point to present any examples as being typical of the behavior of the respective groups.B ， B，和 VIIIB 族元素都是金属。它们形成了各种各样的化合物，在这一点上我们甚至不能举

28、出任何能表现各族元素典型变化的例子。The periodicityof chemicalbehavioris illustratedby the factthat ， excludingthe firstperiod,eachperiodbeginswith a veryreactivemetal.Successiveelementalongtheperiod show decreasing metallic character, eventually becoming nonmetals, and finally, ingroupA, avery reactive nonmetal is f

29、ound. Each period ends with a member of thenoble gas family.除了第一个周期， 化学行为的周期性可以用事实说明，每一个周期以一个非常活泼的金属开始。沿着周期元素显示出了逐渐减少的金属性，最终成为非金属，最后，在A 族，可以发现一个很活泼的非金属元素。每一个周期的结尾是一个稀有气体元素。.02 THE NONMETAL ELEMENTS02非金属元素We noted earlier that -nonmetals exhibit properties that are greatly different from those of the

30、 metals. As a rule, the nonmetals are poor conductors of electricity (graphitic carbon isan 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

31、from the simple diatomic molecules of H2, Cl2, I2,and N2 to the giant molecules of diamond, silicon and boron.很早我们就已经注意到非金属表现出了与金属不一样的特性。一般来说， 非金属是比较差的电子（石墨碳除外）和热的导体；他们是易碎的，通常具有较强的颜色，并表现出很宽范围的熔点和沸点。他们的分子结构，通常是包括了普通的共价键，从简单的双原子分子的H2，Cl 2， I2和 N2到钻石、硅和硼的大分子。The nonmetals that are gases at room tempera

32、ture 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 vaporpressures also indicate small intermolecular forces. Certain properties of a few nonmetals

33、are listed in Table 2.在室温下是气相的非金属是低分子质量的双原子分子和施加了非常小的分子间作用力的稀有气体。随着分子量的增大，我们遇到了一个液体(Br2 )和一个固体 (I2 )，其蒸气压也表明小的分子间作用力。一些非金属的某些性质列在表2中。Table 2 Molecular Weights and Melting Points of Certain NonmetalsDiatomic MoleculesMolecular WeightMelting PointC°ColorH22-239.1'None.N228-210NoneF238-223Pale

34、 yellowO232-218Pale blueCl 271-102Yellow greenBr 2160-7.3Red brownI2254113Gray blackSimple diatomic molecules are not formed by the heavier members of Groups V and VI atordinary conditions. This is in direct contrast to the first members of these groups, N2 andO2. The difference arises because of th

35、e lower stability of bonds formed from p orbitals of the third and higher main energy levels as opposed to the second main energylevel2. The 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

36、strong bond. This is a general phenomenon strong bonds are formed only betweenelementsof the second period. Thus,elementalnitrogenand oxygenformstablemoleculeswith both and bonds,butothermembersof their groupsformmorestable structures basedon bondsonlyat ordinary conditions. Note3that GroupVIIelemen

37、tsform diatomicmolecules,but bondsare notrequiredfor saturationofvalence.通常情况下， V 和 VI 族包括的更重的元素不能形成简单的双原子分子。这与这两个族中所包括的第一种元素是直接相反的，N2 和 O2 。差别的出现是由于与第二主能级相反，第三和更高主能级的p 轨道形成的键稳定性较低。第三和更高周期元素的更大的原子半径和更密的电子云不允许一个强的键所必需的p 轨道很好的平行重叠。这是一个普遍的现象强的键仅仅在第二周期的元素之间形成。因此，氮和氧元素形成了具有和键的稳定分子，但是在通常情况下，这两个族的其他元素可以形成仅

38、仅基于键的更稳定的结构。需要注意的是第VII 族元素形成了双原子分子，但是键不需要用于价态的饱和。.Sulfurexhibitsallotropicforms.Solidsulfurexistsin two crystallineformsandin anamorphousform. Rhombicsulfur is obtainedby crystallizationfrom a suitablesolution,such as CS2, and it melts at 112°C. Monoclinic sulfur is formed by cooling melted sul

39、furandit meltsat 119 °C. Bothformsof crystallinesulfurmeltinto S-gamma,whichiscomposed of S8 molecules. The S8 molecules are puckered rings and survive heating toabout 160 °C. Above 160° C, theS8 rings break open, andsome of thesefragmentscombine with each other to form a highly visco

40、us mixture of irregularly shaped coils. At a range of higher temperatures the liquid sulfur becomes so viscous that it will not pour from its container. The color also changes from straw yellow at sulfur's melting point to a deep reddish-brown as it becomes more viscous.硫具有同素异形体。固态硫存在两种晶形和一种无定形的

41、形式。斜方硫通过在合适的溶液中结晶化获得， 如 CS 2 ，在112 °C 时融化。单斜硫通过冷却融化的硫获得和单斜硫在119 °C时融化。 两种形式的晶体硫融化成S-gamma ，它由 S8分子组成。 S 8的分子起皱成环和加热到160 °C 仍然存在。超过 160 ° C， S8 环被破坏，其中的一些片段相互结合形成一个高粘度的形状不规则的混合物。 在更高的温度范围液态硫变得黏度很高， 以致于在容器中不能倒出。随着变得更粘稠，其颜色也从硫熔点时的稻草黄色变成红褐色。As4 the boiling point of 444° C is app

42、roached, the large-coiled molecules of sulfur arepartially degraded and theliquid sulfur decreasesin viscosity. If thehot liquid sulfur isquenched by pouring it intocold water, the amorphous form of sulfur is produced. Thestructure of amorphous sulfur consists of large-coiled helices with eight sulf

43、ur atoms toeach turn of the helix; theoverall nature of amorphous sulfur is described as3rubberybecause it stretches muchlike ordinary rubber. In a few hours theamorphoussulfurreverts to small rhombic crystals and its rubbery property disappears.随着接近 444 ° C 的沸点，硫的大的螺旋状分子被部分降解和液态硫的黏度降低。如果把热的液态硫

44、倒入到冷却水里骤冷，就会产生无定形硫。无定形硫的结构由具有8 个硫原子的大的螺旋线组成； 无定形硫的总特性被描述成是有弹性的，因为它可以类似于普通的橡胶伸张。几个小时之内无定形硫恢复成菱形晶体，和它的弹性性质消失。.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 pyrit

45、e FeS2, zinc blende ZnS, galena PbS and such, and in common formations ofgypsum CaSO4? 2H2O, anhydrite CaSO4, and barytes BaSO4? 2H2O. Sulfur, in oneform or another, is used in large quantities for making sulfuric acid, fertilizers, insecticides,and paper.硫在工业化学中是一种重要的原材料，它以单质，在火山区域以SO 2，在矿泉水中H 2 S，

46、和各种硫化物出现， 像黄铁矿FeS 2，闪锌矿 ZnS ，方铅矿 PbS 等等，还有石膏 CaSO 4 ?2H 2O ，硬石膏 CaSO 4 ，以及重晶石BaSO 4?2H2O 等普通形态。 硫或以某种方式，用于大量制造硫酸、肥料、杀虫剂、和纸张。Sulfurintheform ofSO2obtained in theroastingofsulfide oresisrecovered andconvertedtosulfuricacid, althoughin previous years muchof this SO2wasdiscardedthrough exceptionally tal

47、l smokestacks. Fortunately, it is now economically favorabletorecoverthesegases,thusgreatlyreducingthis typeof atmosphericpollution.A typicalroasting reaction involves the change:2 ZnS + 3 O2 2 ZnO + 2 SO2在硫化物煅烧中获得的以SO2 形式存在的硫被转化成硫酸，尽管在过去几年许多二氧化硫通过高烟囱排放出去。幸运的是， 现在回收这些气体的成本是较低的，从而这可以大幅度地减少大气污染。典型的焙烧反

48、应如下：2 ZnS + 3 O 2 -2 氧化锌 + 2 二氧化硫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 others6. Instead of a strictlyort

49、hogonal orientation, with the three bonds 90° to each other, the bond angles are only60 ° . 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 ofphosphorus.Thisform

50、ofphosphorus,thewhitemodification,isspontaneouslycombustible in air. When heated to 260° C it changes to red phosphorus, whose structureis obscure. Red phosphorus is stable in air but, like all forms of phosphorus, it should behandled carefully because of its tendency to migrate to the bones wh

51、en ingested, resultingin serious physiological damage.在低于 800 时，磷由四原子分子组成，P4 。它的分子结构提供了三个共价，可预期三个共价是由该原子结构中三个未成对的p 电子形成的，且每个原子都与另外三个相接。不是严格的正交取向，即三个键互成90 °，而是键角仅仅是60 °。这种可能的收缩结构通过4个原子的相互作用来稳定（每一个原子与其他三个原子成键），但是它是化学上最活跃的磷的形式。这种形式的磷、白磷，在空气中能自发燃烧。当加热到260 °C 时，它转变成红磷，其结构是不确定的。红色是在空气中是稳定的，

52、但是，就像所有形式的磷，它应该谨慎处理，因为当摄取时，它倾向于迁移到骨头，这会导致严重的生理伤害。Elemental carbon existsinoneoftwo crystalline structures diamond and graphite.The diamondstructure,basedontetrahedralbonding ofhybridized sp3 orbitals, isencounteredamong GroupIVelements. Wemay expect that as the bond lengthincreases, the hardness of the diamond-type crystal decreases.