Apparatus

One 1 dm beaker
Magnetic stirrer and follower (ideally one coated in Teflon)
Tweezers or tongs



Chemicals

Breakfast cereal with added iron such as 'Special K'

The Demonstration

Measure about 50g (or one serving) of cereal into the beaker. Crush the cereal by hand and add about 500 cm of water.

Stir the mixture using the magnetic stirrer and follower for a few minutes. Remove the follower using the tweezers.

A small but noticeable amount of iron powder will be seen sticking to it.

The amount of iron is small, so it will be necessary to pass the follower around the audience, in a plastic weighing boat for example.

In the following footage, the iron is difficult to detect, but can be seen as the black substance on the follower.