covalence

简明释义

英[kəʊˈveɪləns]美[koʊˈveɪləns]

n. 共价；共价键

英英释义

单词用法

同义词

反义词

例句

1.The results show that the hydrogen of C—H bond on ACFs were substituted by fluorine at different condition. The C—F covalence bond was built at molecular level.

结果表明，随着反应时间和温度的变化，活性炭纤维表面氟取代氢基数目增加，同时在分子水平上形成C—F共价键。

2.Transition metal nitrides belong to a class of interstitial compounds, have the properties of covalence compound, ion crystal and transitional metals.

过渡金属氮化物是一类金属间充型化合物，兼具有共价化合物、离子晶体和过渡金属的性质。

3.C_(60) is one kind of fullerene with high conjugated cage-types structure. Its covalence between two hexagons has high reactivity, which behaves as addition reaction of double bond.

是高度共轭的笼状结构的碳素体，分子结构中六边形环间的共价碳碳双键是富电子区，反应性能与烯烃有类似性，主要表现为双键加成。

4.C_(60) is one kind of fullerene with high conjugated cage-types structure. Its covalence between two hexagons has high reactivity, which behaves as addition reaction of double bond.

是高度共轭的笼状结构的碳素体，分子结构中六边形环间的共价碳碳双键是富电子区，反应性能与烯烃有类似性，主要表现为双键加成。

5.Influence factor and control measure on the preparation of molecular template polymer by non-covalence method were reviewed concisely.

扼要概述了非共价法制备分子模板聚合物的影响因素及控制措施。

6.Water is formed through covalence between hydrogen and oxygen atoms.

水是通过氢和氧原子之间的共价性形成的。

7.Different elements exhibit different levels of covalence based on their electron configurations.

不同元素根据其电子配置表现出不同水平的共价性。

8.The concept of covalence helps explain why certain molecules have specific shapes.

共价性的概念有助于解释某些分子为何具有特定形状。

9.The strength of a bond is often determined by the degree of covalence between the atoms involved.

一个键的强度通常由参与原子之间的共价性程度决定。

10.In chemistry, covalence refers to the sharing of electron pairs between atoms.

在化学中，共价性指的是原子之间共享电子对的现象。

作文

Covalence is a fundamental concept in chemistry that describes the way atoms bond together to form molecules. It refers to the sharing of electron pairs between atoms, which allows them to achieve stability and fulfill their valence shell requirements. This concept is crucial for understanding how different substances interact and combine to create the diverse array of materials we see in the world around us.In a typical covalent bond, two atoms share one or more pairs of electrons. For example, in a water molecule (H2O), each hydrogen atom shares an electron with the oxygen atom. This sharing creates a strong bond that holds the atoms together, resulting in a stable molecule. The strength of these bonds can vary depending on the number of shared electron pairs; single bonds involve one pair, double bonds involve two pairs, and triple bonds involve three pairs.The concept of 共价 bonding is not only important in chemistry but also has implications in biology and materials science. For instance, the structure of DNA, which carries genetic information, relies heavily on covalent bonds. The backbone of the DNA strand is formed by covalent bonds between sugar and phosphate groups, while the bases are connected through hydrogen bonds, another type of interaction. Understanding 共价 bonds helps scientists comprehend how biological molecules function and how they can be manipulated for various applications, such as drug design and genetic engineering.Moreover, the properties of materials are often dictated by the types of bonds present. For example, diamond and graphite are both forms of carbon but have vastly different properties due to the nature of their 共价 bonds. In diamond, each carbon atom is bonded to four other carbon atoms in a three-dimensional tetrahedral structure, giving it exceptional hardness. In contrast, graphite consists of layers of carbon atoms bonded in a planar hexagonal arrangement, allowing the layers to slide over each other easily, making graphite a good lubricant.In addition to its role in forming stable molecules, 共价 bonding also plays a significant role in chemical reactions. When substances react, bonds must break and form, and understanding the nature of these bonds helps chemists predict the outcome of reactions. For example, in the process of combustion, the covalent bonds in hydrocarbons break apart, releasing energy as new bonds form with oxygen atoms.The study of 共价 bonds extends beyond simple molecules to complex structures like proteins and polymers. Proteins, which are essential for life, are composed of long chains of amino acids linked by 共价 bonds. The specific sequence and arrangement of these amino acids determine the protein's shape and function. Similarly, polymers, which are large molecules made up of repeating units, rely on 共价 bonds to maintain their structure and properties. In conclusion, 共价 bonding is a vital concept in understanding the interactions between atoms and the formation of molecules. Its implications stretch across various scientific disciplines, from chemistry to biology and materials science. By grasping the principles of 共价 bonds, we can better appreciate the complexity and beauty of the natural world, as well as harness this knowledge for technological advancements. As we continue to explore the intricacies of molecular interactions, the importance of 共价 bonding will undoubtedly remain a key focus in scientific research and education.

共价是化学中的一个基本概念，描述了原子如何结合在一起形成分子。它指的是原子之间共享电子对的方式，这使它们能够达到稳定性并满足其价壳要求。这个概念对于理解不同物质如何相互作用并结合形成我们周围所见的多样材料至关重要。在典型的共价键中，两个原子共享一对或多对电子。例如，在水分子（H2O）中，每个氢原子与氧原子共享一个电子。这种共享创建了一个强大的键，将原子结合在一起，从而形成一个稳定的分子。这些键的强度可以根据共享电子对的数量而有所不同；单键涉及一对，双键涉及两对，三键涉及三对。共价 键的概念不仅在化学中重要，而且在生物学和材料科学中也有影响。例如，DNA的结构依赖于共价键，它携带遗传信息。DNA链的骨架由糖和磷酸基团之间的共价键形成，而碱基则通过氢键连接，氢键是另一种相互作用。理解共价 键帮助科学家理解生物分子的功能，以及如何操纵这些分子以用于各种应用，如药物设计和基因工程。此外，材料的性质通常由存在的键类型决定。例如，钻石和石墨都是碳的形式，但由于其共价 键的性质，具有截然不同的特性。在钻石中，每个碳原子与四个其他碳原子以三维四面体结构结合，从而赋予其极高的硬度。相比之下，石墨由以平面六角形排列结合的碳原子层组成，使得层能够轻易滑动，从而使石墨成为良好的润滑剂。除了在形成稳定分子中的作用外，共价 键还在化学反应中发挥着重要作用。当物质反应时，必须断裂和形成键，理解这些键的性质帮助化学家预测反应的结果。例如，在燃烧过程中，烃中的共价 键断裂，释放能量，同时与氧原子形成新键。共价 键的研究不仅限于简单分子，还扩展到复杂的结构，如蛋白质和聚合物。蛋白质是生命所必需的，由长链氨基酸通过共价 键连接而成。这些氨基酸的特定序列和排列决定了蛋白质的形状和功能。同样，聚合物是由重复单元组成的大分子，依赖于共价 键来维持其结构和性质。总之，共价 键是理解原子之间相互作用和分子形成的重要概念。它的影响跨越多个科学学科，从化学到生物学和材料科学。通过掌握共价 键的原理，我们可以更好地欣赏自然界的复杂性和美丽，并利用这一知识推动技术进步。随着我们继续探索分子相互作用的复杂性，共价 键的重要性无疑将继续成为科学研究和教育的重点。