A pyramid of energy can never be inverted because energy decreases by tenfold each level. This can't be reversed because energy can't just increase by tenfold. It has to come from somewhere.
<span>Nickel and cobalt are ferromagnets. This means that they are able to acquire magnetism from induction by an external magnetic field. This is caused by the realignment of atoms and unpaired electrons in their structure induced by the magnetic field. Aluminum and copper don't get magnetized because they have few unpaired electrons in their atomic structures. </span>