Ferrofluid is a liquid that has become magnetized, and it’s easily made thanks to this Ferromagnetic powder and water. Mix together, shake and then use the magnet to collect your ferrofluid in the test tube. Or, if you want something you can play with outside of your test tube, then try mixing some of the powder with mineral oil in a dish so you can manipulate your ferrofluid from underneath. Watch as the liquid changes shape and pattern with the movement of your magnet.

Each test tube contains a bag of special magnetic powder and a strong magnet, so when you suspend the powder in a liquid, you can place the magnet near the tube and watch! 

Ferrofluid is a great way to learn about magnet fields and how they work, with a visual representation on this small scale.