This episode explains that an atom's or molecule's magnetic behavior, either diamagnetism or paramagnetism, is determined by its electron configuration. Diamagnetism is present in all substances with paired electrons, resulting in a weak repulsion from magnets. Paramagnetism occurs in substances with unpaired electrons, which are attracted to magnets. It explains how to predict a substance's magnetic properties by examining its orbital diagram for unpaired electrons, using examples like carbon (paramagnetic) and neon (diamagnetic).