Question

what is special about the magnetic substances,so that they are attracted by a magnet?

Answer 1

Magnets don't attract only those metals. Magnetism occurs when a large number of electrons with parallel spins occur within a crystal. The atoms of any element which has electrons with parallel spins behave like a magnet.

Magnetic interaction can be observed in substances which are either ferromagnetic or paramagnetic. Ferromagnetic materials are made of many domains (regions) where electrons have parallel spins. When magnetic field is applied, all of them arrange in same direction.

I hope the answer is clear now.