Which term describes a substance that has paired electrons and is repelled by a magnet?

The term that describes a substance with paired electrons that is repelled by a magnet is diamagnetic. In diamagnetic materials, all the electrons are paired, which means their magnetic moments cancel each other out. As a result, these substances do not have a net magnetic moment and are weakly repelled by an external magnetic field. This repulsion occurs because when exposed to a magnetic field, paired electrons cause a slight rearrangement of the electron cloud, leading to a very weak opposition to the magnetic field.

In contrast, paramagnetic materials contain unpaired electrons that align with an external magnetic field, resulting in a net positive magnetic moment that causes them to be attracted, not repelled. Ferromagnetic materials have a large number of unpaired electrons and exhibit strong magnetism due to magnetic domains that can align in the same direction, leading to significant attraction to a magnet. Superparamagnetic materials are similar to paramagnetic ones but can exhibit strong magnetism when in small particles or nanoparticles, yet they still contain unpaired electrons and are attracted to magnets.

Thus, the characteristics of diamagnetic materials highlight their behavior in response to magnetic fields, which is to be repelled due to the presence of paired electrons.