Our science textbook says it is, but then a scientist friend said it wasn‘t.
Almost all materials are magnetic in the following sense: A material will fall into one of three categories. 1) Paramagnetic 2) Diamagnetic 3) Ferromagnetic Ferromagnetic is what you are talking about only a few pure elements are ferromagnetic. Iron (Fe), Nickel (Ni), Cobalt (Co), and Gadolinium (Gd) are all ferromagnets. But like the others have said, Fe is much stronger than Ni. A paramagnetic material is like a ferromagnet, but very much weaker. A diamagnetic material is actually repelled by a bar magnet (the opposite of paramagnetic), but the force is so weak that you'd have a tough time measuring it. Teach your kids the whole truth even if it is a little over their heads!
Nickel is ferromagnetic. Usually, that means magnetic. It isn't a particularly strong ferromagnet compared to iron or cobalt, which may be what your friend means. The other ferromagnetic elements are dysprosim and gadolinium, neither of which are common and both have Curie temperatures below room temperature, so they're kind of useless in most cases as magnetic materials.
