sentence2_structure: certain other metals<>can form<>a(n) electromagnet
sentence1: The magnet is wrapped with a coil of  wire that forms an electromagnet, wound so that its polarity is the opposite of that of the permanent magnet.
sentence2: A solenoid or coil wrapped around iron or certain other metals can form a(n) electromagnet.
question: A solenoid or coil wrapped around iron or certain other metals can form what kind of magnet?