Paramagnetic substances are materials that have unpaired electrons in their atomic or molecular structure. This characteristic allows them to be attracted to external magnetic fields. When placed in a magnetic field, the unpaired electrons align with the field, causing the material to exhibit magnetism. Common examples of paramagnetic substances include oxygen, iron(III) oxide, and certain metal ions like manganese. Unlike ferromagnetic materials, which retain magnetism after the external field is removed, paramagnetic substances only exhibit magnetism while in the presence of a magnetic field.