You make a metal paper clip float on water. (Really!)
The Science Secret:
The secret involves the water’s surface tension, the tendency for water molecules on the surface to be attracted to each other. This is the reason why when a glass of water is filled to the brim and small objects are added, you can see the water bowing up over the glass. And it’s also the reason why small insects and such can rest on the surface of still water.
The trick involves not break the water’s surface tension when resting an object, in this case, a metal paper clip, on the water’s surface.
A glass or bowl of water
Two metal paperclips