covalent bond

简明释义

共价键

英英释义

例句

1.In a water molecule, each hydrogen atom forms a covalent bond with the oxygen atom.

在水分子中，每个氢原子与氧原子形成一个共价键。

2.When two nonmetals react, they typically form covalent bonds.

当两个非金属反应时，它们通常形成共价键。

3.The strength of a covalent bond depends on the atoms involved.

一个共价键的强度取决于参与的原子。

4.The double covalent bond between carbon atoms in ethylene gives it unique properties.

乙烯中碳原子之间的双共价键赋予它独特的性质。

5.Carbon can form four covalent bonds with other atoms, making it versatile in organic compounds.

碳可以与其他原子形成四个共价键，使其在有机化合物中非常灵活。

作文

In the realm of chemistry, understanding the various types of bonds that hold atoms together is fundamental to grasping the nature of matter. One of the most significant types of chemical bonds is the covalent bond. A covalent bond is formed when two atoms share one or more pairs of electrons, allowing each atom to attain a full outer shell of electrons, which is essential for stability. This sharing of electrons occurs primarily between nonmetals, as these elements have similar electronegativities and can effectively share their valence electrons.The concept of a covalent bond can be illustrated through the example of water (H2O). In a water molecule, each hydrogen atom shares its single electron with the oxygen atom, which has six electrons in its outer shell. By sharing, the hydrogen atoms and the oxygen atom effectively fill their outer shells, resulting in a stable molecule. This simple yet profound interaction highlights the importance of covalent bonds in forming the compounds that are essential for life.Moreover, covalent bonds can vary in strength and length, depending on the number of shared electron pairs. A single covalent bond involves one pair of shared electrons, while double and triple bonds involve two and three pairs, respectively. For instance, in a carbon dioxide (CO2) molecule, the carbon atom forms two double covalent bonds with two oxygen atoms, leading to a linear molecular structure that is crucial for its function as a greenhouse gas.The significance of covalent bonds extends beyond simple molecular formation; they play a vital role in the properties of substances. Compounds held together by covalent bonds often exhibit unique characteristics, such as low melting and boiling points, compared to ionic compounds. This is due to the fact that covalent bonds tend to form discrete molecules rather than extensive lattice structures, as seen in ionic compounds. Consequently, many organic compounds, which are primarily composed of carbon and hydrogen, possess distinct physical and chemical properties that are essential for biological processes.In addition to their role in molecular stability, covalent bonds are also crucial in the formation of macromolecules, such as proteins and nucleic acids. Proteins, which are composed of amino acids linked by covalent bonds, perform a myriad of functions in living organisms, including catalyzing biochemical reactions and providing structural support. Similarly, nucleic acids like DNA and RNA rely on covalent bonds to connect nucleotides, ensuring the integrity of genetic information across generations.In conclusion, the covalent bond is a cornerstone of chemical bonding that facilitates the formation of stable molecules and compounds. By sharing electrons, atoms achieve greater stability and form the basis of countless substances that are vital for life. Understanding covalent bonds not only enhances our comprehension of chemistry but also illuminates the intricate connections that underpin the biological world around us. Thus, the study of covalent bonds is essential for anyone looking to delve deeper into the fascinating field of chemistry and its applications in everyday life.

在化学领域，理解将原子结合在一起的各种类型的键是掌握物质性质的基础。其中最重要的化学键之一就是共价键。共价键是在两个原子共享一对或多对电子时形成的，这使得每个原子能够获得完整的外层电子，这对于稳定性至关重要。这种电子的共享主要发生在非金属之间，因为这些元素具有相似的电负性，能够有效地共享它们的价电子。共价键的概念可以通过水（H2O）的例子来说明。在水分子中，每个氢原子与氧原子共享其单个电子，而氧原子在其外层有六个电子。通过共享，氢原子和氧原子有效地填满了它们的外层，从而形成一个稳定的分子。这种简单而深刻的相互作用突显了共价键在形成生命所必需的化合物中的重要性。此外，共价键的强度和长度可能会有所不同，这取决于共享电子对的数量。单个共价键涉及一对共享电子，而双键和三键分别涉及两对和三对。例如，在二氧化碳（CO2）分子中，碳原子与两个氧原子形成两个双共价键，导致其线性分子结构对其作为温室气体的功能至关重要。共价键的重要性不仅仅局限于简单的分子形成；它们在物质的性质中也发挥着至关重要的作用。由共价键结合的化合物通常表现出独特的特性，例如与离子化合物相比，熔点和沸点较低。这是因为共价键倾向于形成离散分子，而不是像离子化合物那样形成广泛的晶格结构。因此，许多有机化合物主要由碳和氢组成，具有独特的物理和化学性质，这些性质对生物过程至关重要。除了在分子稳定性中的作用，共价键在大分子的形成中也至关重要，例如蛋白质和核酸。蛋白质由通过共价键连接的氨基酸组成，执行生物体中的许多功能，包括催化生化反应和提供结构支持。同样，核酸如DNA和RNA依赖于共价键连接核苷酸，确保遗传信息在世代之间的完整性。总之，共价键是化学键的基石，它促进了稳定分子和化合物的形成。通过共享电子，原子实现了更大的稳定性，并构成了无数对生命至关重要的物质的基础。理解共价键不仅增强了我们对化学的理解，还阐明了支撑我们周围生物世界的复杂联系。因此，研究共价键对于任何希望深入探讨化学及其在日常生活中应用的领域的人来说都是必不可少的。