Oxygen (O2) primarily exhibits London dispersion forces as its intermolecular forces. These forces are a type of van der Waals force and are present in all molecular substances, although they are the weakest form of intermolecular interaction.
In the case of O2, the molecules are nonpolar due to the equal electronegativity of the two oxygen atoms. As a result, there are no permanent dipole-dipole interactions or hydrogen bonding occurring within or between the O2 molecules. Instead, the London dispersion forces arise from the temporary dipoles that occur when the electron distribution around the molecules shifts momentarily. This can create a fleeting positive and negative charge that induces a similar effect in neighboring molecules, allowing them to attract one another, though very weakly.
Overall, while O2 might not have strong intermolecular forces, these London dispersion forces are sufficient to facilitate interactions between the molecules at low temperatures, where O2 can exist in liquid form.