Today we did a small review of previous concepts, including the mole, molar mass and intramolecular bonding. We then discussed intermolecular bonding in further detail. More time was spent expanding on the concept of dipoles and polar bonds, and how this polarity, which results from differences in electronegativity, leads to hydrogen bonding and / or dipole-dipole interactions. We also discussed van der Waals contacts, and finished the lesson on an exercise in which the students predicted all intermolecular forces that occur in homogenous mixtures of various compounds.