Can unmagnetized steel be magnetized?
Yes all that is necessary is to line up the free electrons in all the atoms in a sample of steel or iron in the same direction.
One way of magnetizing steel is to wrap electric wire around the steel multiple times and then run a current through the wire. This will create an electro magnet. The steel will remain somewhat magnetized after being in the electro magnetic field.
A moving electric current creates a magnetic field according to the left hand rule. The fingers of the left hand represent the moving electrons and the thumb indicates the direction of the magnet field created by the moving electrons.
A piece of steel or iron can be "stroked" with a strong magnet. Repeated stroking in the same direction will orienate the electrons movement in the atoms so that the magnetic field of all ( most) of the atoms are facing the same direction. This can also be accomplished by placing a piece of steel or iron is a strong magnetic field and leaving it there for a period of time.
( note it is easier to magnetized a piece of soft iron than hardened steel. The harder the steel the harder it is to magnetize it.
Iron Fe number 26 has 8 valance electrons. These valance electrons are in the 4s and 3 d orbitals.
There are five 3 d orbitals. The 4s and 1 3d orbital have two electrons one with a positive spin and one with a negative spin which cancels each other out.
There are four 3 d orbitals that have only one electron. If all four have the same spin ( either positive or negative) this creates a magnetic field due the the movement of the electrons. If the magnetic fields created most of the atoms are pointing the same direction the piece of Ferrous material ( steel or iron) will be magnetic.
Yes, it can.
All you have to do is stroke the steel with a strong magnet.
The magnetic fields of atoms are grouped together and aligned in small regions called magnetic domains.
They are like little magnets inside the steel.
In the unmagnetized steel, the domains are pointing in all directions.
When you stroke a magnet repeatedly across the steel in a given direction, the domains line up in the same direction.
The steel becomes a magnet.