Question

How is the strength of London dispersion forces related to the number of electrons?

Answer 1

Hint: The London dispersion force is defined as the instantaneous dipole induced dipole attractions. This type of attraction exhibits between the two or more non polar molecules. These forces are weaker than the other intermolecular forces because these are generated by the random motions of electrons on atoms within the molecule.

Complete step by step answer:
- In this force of attraction the electrons are being unequally distributed about the nucleus in the atom which tends to induce some amount of dipole in the atom. Now when the other molecule or the atom tries to come in contact with this induced dipole, it can cause distortion which can further lead to the generation of the electrostatic attraction between the atoms or the molecules.
- So due to this these London dispersion forces are considered as the weak or the temporary attractive forces because they tend to form the temporary dipoles in the non polar molecule. when the electrons are being displaced in two adjacent atoms in a way such that the atoms could get some temporary dipoles, they then get attracted by the London dispersion force.
- In short the London dispersion force depends on the surface area of the particles which are interacting. So if the number of electrons are more then the size of the atom would increase and so the London dispersion force would be strong. The high number of electrons would increase the probability of forming the induced dipole or the polarizability which tends to make the interaction strong.

Note: The force of attraction is defined as the attraction which is found between the molecules which keeps them in a position. The London dispersion force is generally found in halogens such as fluorine, bromine, iodine. It is also found in the noble gases or the inert gases such as Neon, Helium, Argon. These forces are caused by the random motion of the electrons in the atoms of the molecule.