Which term describes a substance that has several unpaired electrons per atom and is strongly attracted to magnets?

• A. Paramagnetic
• B. Diamagnetic
• C. Nonmagnetic
• D. Ferromagnetic

Answer: (D)

The main idea is how electrons’ spins create magnetism in a material. When atoms have unpaired electrons, their magnetic moments can be attracted to an external magnet. If there are unpaired electrons but the material is only weakly attracted, that’s paramagnetic behavior; if the electrons are all paired, the material is diamagnetic and is actually repelled. When many unpaired electrons interact so that their magnetic moments align in regions called domains, the material shows a strong attraction to magnets and can retain magnetization—this is ferromagnetism. The strong attraction described in the question points to ferromagnetic behavior, not just a weak paramagnetic attraction or a diamagnetic repulsion. Common ferromagnets are iron, cobalt, and nickel, which exhibit this strong, cooperative magnetic ordering.