Each group needs:
- rubber-coated NdFeB magnet
- paper holder for iron filings
- 1 teaspoon of iron filings
- clear bottle of prepared mineral oil*
- 1 sheet of paper, 8.5 x 11 inches (20.32 x 27.94 cm)
- masking tape
* Remove labels on a clear plastic bottle of mineral oil. Cut ~1 teaspoon of fine-grade steel wool into small shards. Put the steel wool shards into the bottle and recap. After shaking, the bottle displays magnetic fields in three dimensions.