You need a large bright, shiny steel nail and a jam jar for this activity. You also need a lot of patience!

Place the nail in the jam jar and fill it with tap water until half the nail is under water.

Put on the lid (to stop the water in the jar from drying out).

Take a digital picture of the nail from the side.

Take more pictures, one a week.

You should notice the nail goes rusty and that eventually the rust starts to fall off into the water.

Rusting is a big problem for steel. This is why steel things used outdoors are painted.