How To Wire Wrap Jewelry?

Why do you need to wrap a wire around a metal core to make a electromagnet?

• doesn't the current running through the wire create a magnetic feild (therefore being a magnet) by itself like why would you need a iron stick or something like that to wrap the wire around it to create a electromagnet? And if you need something to wrap the wire around why can't you just use any metal?

• Answer:

  You can use just a wire; it's just that putting in iron amplifies the effect. Iron, cobalt, nickel, and a lot of their alloys are ferromagnetic, which means that each atom is a tiny magnet itself. These magnets are not quite strong enough to line each other up, but with a push from the magnetic field of a coil, they can all line up and add their strength to the coil's strength. Most materials are not ferromagnetic; while most atoms are at least a little bit magnetic, only Fe, Co, and Ni (as far as I know) are strong enough to significantly help boost the field of a coil. Magnetite is a special mineral which *is* strong enough to line up even without a boost.