Task: Text Categorization
Input (English): In NMR, the nucleus independent chemical shift is used as a reference when working with molecules that exhibit this property. Also in NMR, molecules with this property exhibit a diamagnetic ring current. If half the vertices of a molecule's structure lie fully in the lower half of a Frost circle, it will have this property, which corresponds to no occupation of antibonding molecular orbitals. Molecules with this property generally show a high degree of unsaturation, but prefer substitution reactions to addition reactions. A molecule is said to have this property if it contains a fully-conjugated cyclic system. Four n plus two pi electrons is one criteria for this property put forth by Huckel. For 10 points, name this property of molecules like benzene, which exhibit unusual stability.
Output (English): Science