Yes - if you have a powerful enough magnet !
Yes - if you can pick it up with a magnet, it has iron in it. That is why they call substances you can pick up with a magnet "ferromagnetic" - ferrous (the ferro part of ferromagnetic) is Latin meaning (roughly) "of iron", or "containing iron".
No
An electro magnet.
No
No
It will pick up the nails the same way a bar magnet would do!
No gold is not ferro magnetic. So it will not be picked by a magnet
Try a magnet. A magnet picks up iron. It does not pick up aluminum.
The easiest way to check for steel is to use a magnet. A magnet is going to pick up steel and will not pick up metals that do not contain iron.
look at the bottom of the washer reservoir
A magnet is built in the crane to pick up cars and other vehicles.
with a magnet