User: Classify the following by how they are affected by a strong permanent magnet as one of "attract", "repel", "nothing": iron nail, paper clips, a tin can, a compass, a plastic cup, a glass window, a leather wallet, a brick, a magnet of opposite polarity, pyrolytic carbon sheet.
Assistant: Items that are strongly or weakly attracted are called "ferromagnetic" and "paramagnetic", respectively. These include: iron nail, paper clips, a tin can, a compass.
Items that are repelled by a magnet are either "paramagnetic" or themselves permanent magnets of the opposite polarity, including: a magnet of opposite polarity, pyrolytic carbon sheet. Items that are not affected by a permanent magnet are called "nonmagnetic" and include: a plastic cup, a glass window, a leather wallet, a brick.