What type of materials cannot be magnetized at all?

Materials that cannot be magnetized are typically classified as non-magnetic. Copper and brass are both non-ferrous metals; copper is a good conductor of electricity but does not exhibit ferromagnetism, which is necessary for magnetization. Brass, an alloy primarily made of copper and zinc, inherits copper’s non-magnetic properties, making it unsuitable for becoming magnetized as well.

In contrast, iron and cobalt are ferromagnetic materials, meaning they can be magnetized due to their atomic structure, allowing them to align their magnetic domains. Platinum and titanium also do not possess magnetic characteristics, but they have different properties compared to copper and brass. Aluminum has some weak paramagnetic properties, and nickel is ferromagnetic, capable of being magnetized.

Thus, the designation of copper and brass as materials that cannot be magnetized aligns with the fundamental concepts of magnetism in materials science.