Ferrofluid

Ferrofluid is a suspension of magnetically susceptible particles in oil. When placed near a magnet, it forms into mind-meltingly awesome patterns which illustrate the shape of the magnetic field.

[|Check it out.]

Kit contents
Our ferrofluid demo kit lives in the GK-12 room. It contains All packaged handsomely in a small cardboard box.
 * a 4oz bottle of ferrofluid
 * 4 eyedroppers
 * 2 petri dishes
 * 2 neodymium magnets
 * MSDS

Usage
Dispense one or two eyedropperfuls into a petri dish. Make patterns by placing one of the magnets underneath the dish, as you would with iron filings.

Ferrofluid is not hazardous but it will stain like crazy. Be careful not to move magnets too close to the edge of the dish - this will cause a spill.

The demo is best seen up close, but doesn't show up too well on the document camera. I did the demonstration for 4 or 5 kids at a time, while other groups were working with iron filings on a paper plate. The two demos tie nicely into one another.

Disposal
A dish of ferrofluid will be re-usable for days.

When done, I soaked the excess into paper towels, threw them out, and rinsed the dish in the sink with soap.