What is it about most metals that make them magnets? Describe what is happening in the atoms.?

Answer 1

This applies almost exclusively to ferrous metals.
The metal consists of tiny crystals of iron. These crystals are magnetic but because they are distributed randomly there is no net effect. If a magnet field is applied in one direction the crystals (domains) have their magnetic fields lined up and the whole piece becomes a magnet.

Answer 2

in ferromagnetic metals, unpaired electrons are present which generate a local magnetic field, and electron spins in nearby atoms tend to become correlated (so that all have either 'up' or 'down' spin) which generates a large scale magnetic field.