Final answer:
Non-ferrous metals such as aluminum, copper, and brass are not attracted to magnets because they do not exhibit strong magnetic properties like ferromagnetic materials.
Step-by-step explanation:
Magnets attract only certain types of metals, specifically those that are ferromagnetic, such as iron, cobalt, and nickel. These materials can either be naturally magnetic or can be magnetized to become permanent magnets. However, non-ferrous metals do not exhibit these strong magnetic properties and are thus not attracted to magnets. Examples of non-ferrous metals include aluminum, copper, and brass, which are commonly used in various applications due to their other physical properties.