How molecules become magnetic ... and the resulting wonderland

In everyday life, the word “magnetism” most often refers to solid materials, metals, alloys, oxides. As for molecules, they are considered to be isolated, non-magnetic objects. Nevertheless, to be or not to be (magnetic) is not the appropriate question: everything is magnetic; the true problem lies in determining how. The purpose of this lecture is to illustrate the magnetism of molecules through some experiments.