What Types of Intermolecular Forces Exist in CH4 Molecules?
The molecule known as CH4, or methane, is affected by van der Waals forces between individual molecules. Van der Waals forces are created when the molecule temporarily becomes electrically charged due to the natural movement of electrons across the shared bonds of the atoms making up the molecule.
Methane’s atoms are covalently bonded, meaning that the electrons from each atom of the molecule are shared throughout the molecule. This sharing is not always equal, and sometimes electrons wind up being collected on one side of the molecule, creating an overall negative charge on that side, and an overall positive charge on the opposite side. This is called a dipole moment. The unequal distribution of electrons temporarily makes the molecule attract other molecules.
The various kinds of van der Waals attractions are named according to whether the molecules mutually and spontaneously created temporary charges, or if one molecule induced a charge in another due to close contact. London dispersion forces are caused by one molecule inducing a charge in another, and are prevalent in methane. The bonds formed by van der Waals forces are very short-range but can be very strong within that range.