* Intermolecular forces: The forces that hold molecules together are called intermolecular forces. Non-polar molecules primarily interact through weak London dispersion forces, which arise from temporary fluctuations in electron distribution. Polar molecules, on the other hand, have stronger dipole-dipole interactions and sometimes hydrogen bonding.

* Solubility: "Like dissolves like" is a good rule of thumb. Non-polar molecules will dissolve better in non-polar solvents, while polar molecules will dissolve better in polar solvents. This is because the intermolecular forces between similar molecules are stronger, allowing for better mixing.

Example:

* Oil and water: Oil is non-polar, and water is polar. They don't mix well because the strong hydrogen bonds in water are not easily disrupted by the weak London dispersion forces in oil.

In summary: Non-polar molecules are attracted to other non-polar molecules due to the weaker, but still present, London dispersion forces.