Which pair are examples of ferromagnetic materials?

Which pair are examples of ferromagnetic materials?

• A. Gold and Silver
• B. Copper and Aluminum
• C. Iron and Nickel
• D. Tin and Lead

Answer: (C)

Ferromagnetism is when a material can develop a strong, permanent magnetization because the magnetic moments of many atoms align together due to exchange interactions. This creates large regions called domains that can stay aligned even after an external magnetic field is removed. Iron and nickel are classic examples because they have unpaired electrons whose spins couple strongly, causing widespread alignment of magnetic moments. This makes them magnetizable and capable of retaining magnetization. Other metals like gold and silver are diamagnetic, meaning they create only a tiny opposing field and don’t hold magnetization. Copper and aluminum are weakly paramagnetic or nearly non-magnetic, so they don’t form permanent magnets. Tin and lead are also diamagnetic.

Ferromagnetism is when a material can develop a strong, permanent magnetization because the magnetic moments of many atoms align together due to exchange interactions. This creates large regions called domains that can stay aligned even after an external magnetic field is removed.

Iron and nickel are classic examples because they have unpaired electrons whose spins couple strongly, causing widespread alignment of magnetic moments. This makes them magnetizable and capable of retaining magnetization.

Other metals like gold and silver are diamagnetic, meaning they create only a tiny opposing field and don’t hold magnetization. Copper and aluminum are weakly paramagnetic or nearly non-magnetic, so they don’t form permanent magnets. Tin and lead are also diamagnetic.