伦敦力是什么？

中文版

伦敦力，也被称为伦敦分散力，是描述分子间相互作用力的一种概念。它是由英国物理学家弗雷德里克·伦敦在20世纪初提出的，用以解释非极性分子间的弱相互作用。伦敦力是一种瞬时偶极-瞬时偶极相互作用，由于分子中的电子运动是随机的，某一瞬间正电荷中心和负电荷中心不重合，形成了瞬时偶极。当两个非极性分子相互接近时，它们的瞬时偶极之间会产生吸引力，这种吸引力就是伦敦力。

伦敦力虽然不如离子键和共价键那样强烈，但在许多化学和物理过程中都扮演着重要角色。例如，在气态分子和凝聚态物质中，伦敦力是维持分子间距离和稳定性的重要因素。此外，伦敦力还决定了许多物质的物理性质，如熔点、沸点、溶解度等。

伦敦力的存在不仅解释了非极性分子间的相互作用，也为我们提供了理解更复杂分子间相互作用的基础。通过深入研究伦敦力，我们可以更好地理解分子间的相互作用，从而设计出更有效的材料和药物。

英文版

What is the London Force?

The London force, also known as the London dispersion force, is a concept describing the interaction between molecules. Named by British physicist Frederick London in the early 20th century, it explains the weak interactions among non-polar molecules. The London force arises from the instantaneous dipole-instantaneous dipole interaction, where the random motion of electrons within a molecule can cause a temporary separation of positive and negative charge centers, creating an instantaneous dipole. When two non-polar molecules approach each other, their instantaneous dipoles attract each other, giving rise to the London force.

Although not as strong as ionic or covalent bonds, the London force plays a crucial role in many chemical and physical processes. For instance, in gaseous molecules and condensed matter, the London force is a significant factor maintaining intermolecular distances and stability. Furthermore, the London force determines many physical properties of substances, such as melting points, boiling points, and solubility.

The existence of the London force not only explains the interactions among non-polar molecules but also provides a foundation for understanding more complex intermolecular interactions. By delving into the London force, we can gain a deeper understanding of intermolecular interactions, enabling the design of more effective materials and drugs.