Diamagnetism is a form of magnetism that occurs in materials that do not have unpaired electrons, resulting in a very weak repulsion from magnetic fields. This property arises due to the induced magnetic moment created by the motion of electrons in response to an external magnetic field. Unlike paramagnetic or ferromagnetic materials, diamagnetic substances tend to be repelled by magnetic fields, and this characteristic is linked to their electron configurations and the overall behavior of elements in the periodic table.