Testing for magnetic properties. Only certain materials (such as iron, steel and other metals) have the electronic and molecular structure needed for magnetism to be present. As seen by the attraction displayed here, metal is a magnetic material. The metal pieces have become magnetized and are aligning with the magnetic field and moving towards the magnet. Magnetism is a stronger force than gravity, and a relatively small magnetic field can overcome the weight of the metal pieces and pull them upwards from the petri dish. In the other image sugar which has no magnetic prperties is unaffected by the magnet.