How to make an electromagnet
You can make an electromagnet by having a core of magnetic material (such as iron) surrounded by a coil of wire through which an electric current is passed to magnetise the core.
"Electromagnet" is electric and magnet pushed together.
Take a length of thin, insulated copper wire and wrap it tightly around the nail and make sure you leave two lengths of wire at either end.
Remove the insulation from the ends and curl the bared wire around to make sure you get better contact with your battery.
Line up the two ends of the copper wire with the battery, one on the +ve end and one on the -ve end.
The battery will get very warm so use a cloth or tea towel to hold the ends of the wire on each end of the battery.
Now hold the wire and the nail up against the metal objects.
The iron nail has become a magnet.
This works because the electricity flowing through the copper wire has aligned the atoms in the nail to a north and south facing pole, therefore producing a magnetic field around the nail.