This activity demonstrates how a ferrofluid acts under the presence of a magnetic field. A penny is lifted to the top of a ferrofluid liquid when a magnetic field is introduced because of a change in the properties of the fluid. Students will be able to explore the differences between ferrofluids and a normal fluid.
- EMG-905, a mineral oil-based ferrofluid with a saturation magnetization of 400 gauss obtained from Ferrofluidics Corporation.
- Strong magnet (cow magnet, bar magnet, or rare earth magnet).
- Petri dish
- Penny or other small coin