Which metals are ideal examples of materials that could be separated using magnetism?

Iron, nickel, and cobalt are ideal examples of materials that can be separated using magnetism because they are ferromagnetic materials. Ferromagnetic substances have unpaired electrons that create a net magnetic moment, allowing them to be attracted to magnetic fields. This property makes it feasible to use magnets for separation processes in industrial and laboratory settings, where these metals can be effectively isolated from mixtures or solutions.

In contrast, the other options contain metals that do not exhibit significant magnetic properties. For example, copper and zinc are non-magnetic, meaning they do not respond to magnetic fields and cannot be easily separated using magnetization techniques. Similarly, aluminum and gold also lack the ferromagnetic characteristics necessary for magnetic separation, and lead and titanium do not possess the magnetic properties that would allow for effective separation with magnets. Thus, iron, nickel, and cobalt stand out as the most relevant examples for magnetic separation.