<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>
Heating of the Earth due to the Sun's rays causes convection currents of air upwards. The warm air moves upwards, while cool air from nearby regions fills in the lower areas.
<span>Heating of the Earth can cause warm water currents that flow from hot areas like near the equator and tropical areas, while cold water currents flow from the arctic and antarctic regions and the temperate regions. </span>
Hydroxyapatite is the major component of bone that contributes to its hardness.
