Given a scientific passage and an answer, generate a question for the given answer.

Passage: Magnetism is the ability to be attracted by a magnet and to act as a magnet. Only ferromagnetic materials have this property. They include iron, cobalt, and nickel. When these materials are magnetized, they become temporary or permanent magnets. Magnetite is a natural permanent magnet. Answer: magnetism
What is the ability to be attracted by a magnet and to act as a magnet?