Question

What is the force that can cause two pieces of iron to attract each other?

Answer 1

The magnet force. The free electrons in them are free to move because of the conductivity of the metal.

Answer 2

ferromagnetism

Answer 3

this is caused by the existence of unpaired electrons i.e. occupy an orbital singly

Answer 4

ps. conductivity and magnetism are not the same thing

Answer 5

i forgot to mention that the unpaired electrons need to have parallel spins, if they have antiparallel spins they were not magnetic, a term called antiferromagnetism.