The term "keesom force" is a scientific term used in physics to describe an electrostatic interaction between atoms or molecules. It is named after Willem Hendrik Keesom, a Dutch physicist who first described this force. The correct spelling of "keesom force" is /ˈkiːsəm fɔːrs/ in IPA phonetic transcription. The word "keesom" is pronounced with a long "e" sound followed by a short "s" sound, while "force" is pronounced with a silent "e" at the end.
Keesom force, also known as the Keesom interaction, refers to the attractive interaction that occurs between two electrically neutral but polar molecules due to fluctuations in their electronic charge distribution. It is a type of intermolecular force, specifically an intermolecular dipole-dipole interaction, named after the Dutch physicist Willem Hendrik Keesom.
Keesom force is a consequence of the temporary imbalances in electron charge density that occur within molecules. At any given time, the electrons in a molecule can be distributed unevenly, resulting in transient dipoles. These dipoles induce opposite dipoles in nearby molecules, leading to an attractive force between them.
Unlike other intermolecular forces, such as London dispersion forces and hydrogen bonding, Keesom forces primarily arise from the interaction between permanent molecular dipoles. It is highly dependent on the polarizability of the molecules involved. The magnitude of the Keesom force increases with the magnitude of the dipole moments of the molecules and decreases with the separation distance between them.
Keesom forces have significance in various areas of science and technology. They play a crucial role in determining the physical properties of liquids and solids, such as their boiling points, melting points, and viscosity. Understanding Keesom forces is essential in fields like chemistry, physics, and material science, as they influence the behavior and interactions of many substances, especially polar molecules.
The term "Keesom force" is named after Willem Hendrik Keesom, a Dutch physicist who first described this force in 1912. So, the etymology of the word can be traced back to the surname of the scientist who discovered it.