1. Place the magnet in a scrap iron (or pin) and pull it out. The magnet attracts iron chips (or pins) as shown in Figure 3.22-1.
2. The magnets are placed in iron filings (or pins) across certain materials (such as wood, glass), and the magnets still have iron absorption.
3. Put the magnet into wood chips or copper flakes (powder). Magnets cannot suck up wood chips or copper.
Observe the key points: Both ends of the magnet attract a lot of iron filings or pins, but they cannot attract wood chips or copper (powder) and other substances.
Conclusion: Magnets are the most magnetic at both ends and are called magnetic poles. The substance that can be attracted by a magnet is called a ferromagnetic substance.
Editor's Note: This small experiment can be supplemented by the "electromagnetics" part of the physics experiment teaching, in order to cultivate and improve students' experimental ability and quality.