Today in science my group and I made a temporary magnet like last science, but this time we wrapped one quarter of wire around the bolt and then we learned it can not hold any paper clips. Then we tried two quarters of wire on the bolt, but this time it worked and three paper clips attract to the electro magnet, we thought it stuck because it had more wire. For the next one we wrapped half of the bolt with wire and we got six clips on the bolt. on the last one we got all the paper clips! With all the wire I learned that when you wrap all the wire on the bolt it is stronger. My question is how do scientist/people find out what materials to make an a electro magnet?