What decreases as the strength of the attractive intermolecular forces increases?

The vapor pressure of a liquid The vapor of pressure of a liquid decreases as the strength of the attractive intermolecular forces increases. The vapor pressure is defined as the amount of gas of a compound that is in equilibrium (thermodynamic equilibrium) with the liquid or solid.

As the intermolecular forces increase, the molecules cannot break out of the solid or liquid. Thus, the particles remain in a solid or liquid state. The stronger the intermolecular forces, the stronger the interactions that hold the substance together, the lower the vapor pressure of a liquid at the given temperature, and the harder it is to vaporize the material.