London Dispersion Forces PDF

LONDON DISPERSION FORCES FRITZ LONDON (1900-1954) London Dispersion Forces are named after Fritz London, a German-American physicist, who first decribed these forces in 1930. London proposed that even in nonpolar molecules, temporary flu...

LONDON DISPERSION FORCES FRITZ LONDON (1900-1954) London Dispersion Forces are named after Fritz London, a German-American physicist, who first decribed these forces in 1930. London proposed that even in nonpolar molecules, temporary fluctuations in electron distribution could lead to weak interactions between molecules. NOTE: London Dispersion Forces is sometimes called a “Van der Waals Force” it is a general term that describes any attractive intermolecular force between molecules.  What is London Dispersion Force? The London dispersion force is the weakest intermolecular force. The unequal distribution of electrons about the nucleus in an atom can induce some dipole in the atom. When another atom or molecule comes in contact with this induced dipole, it can be distorted that leads to an electrostatic attraction between either atoms or molecules. Dispersion forces are present between all molecules, whether they are polar or nonpolar. Dispersion - means the way things are distributed or spread out.  KEY FEATURES: One TEMPORARY DIPOLES These forces occur when electrons in an atom or molecule become unevenly distributed, creating a temporary dipole Two INDUCED DIPOLES The temporary dipole in one molecule induces a dipole in a neighboring molecule, resulting in an attractive force.  Examples of London Dispersion Force Noble Gases Nonpolar Molecules Halogens Helium (He) Oxygen (O2) Iodine (I2) Neon (Ne) Carbon Dioxide (CO2) Bromine (Br2) Argon (Ar) Methane (CH4) these are nonpolar, so the these are nonpolar, and also these are example of molecules only intermolecular force they expedience London Dispersion where Dispersion Forces are experience is London Forces. significant due to their large size and electron count, which lead to Dispersion Force. stronger temporary dipoles.  Summary: London Dispersion Forces are weak intermolecular forces present in all molecules, even nonpolar ones. They are caused by temporary dipoles that form due to fluctuations in electron distribution, leading to attractive forces between molecules. These forces increase with the size and electron count of molecules, making them stronger in larger molecules. Although they are weak, they play a significant role in the properties of gases and liquids, especially for nonpolar substances Thanks for listening!