Another interesting things to note about molecular properties that result from IMFs is that they are not really properties of a single molecule, but the result of an ensemble or large system of many molecules, which must be viewed as a whole, and not as individual molecules. Simple speaking, an individual molecule can not have a boiling point, which is really a function of the interaction between a large number of molecules. So the boiling point of water is not a property of a water molecule, but a bunch of water molecules. So, if you have a liquid at a given temperature there is a distribution of velocities, some of the molecules have enough kinetic energy to escape the attractive cohesive forces on the surface and enter the vapor phase, while others do not. So the vapor pressure above a liquid is also influenced by intermolecular forces. The point is some properties of a substance, like it's atomic mass or its polarity, are the property of a single molecule, while others, like the melting point or vapor pressure, are the properties of a huge number (ensemble) of molecules

At a given temperature, would it be easier to vaporize a light molecule or a heavy molecule?

Hydrogen Bonding (special type of dipole-dipole)

not all matter is composed of molecules.

Sublimation: The transition from the solid phase to the gas phase Deposition: The transition from the gas phase to the solid phase

Condensing

Plasma State