Ferrofluid is a fascinating material to play with; a seemingly magnetic fluid that can move, dance, and form incredible patterns when magnets are brought close to them. Ferrofluid is fun to play with, but the iron oxide powder required to make it can be difficult to find. With this activity, you can make your own version of ferrofluid, using only iron filings, a test tube, and some water! Grab a strong magnet, and get ready to dance your way through the science of magnetism!
Test tube with cap
Strong magnet (neodymium or ceramic magnets work well
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Put three small pinches of iron filings into your test tube.
Fill your test tube with water, and tightly close the cap, creating a water tight seal.
Watch as the iron settles to the bottom of the test tube. If your test tube gets dropped or shaken, just let it sit for a few minutes to let everything settle again.
Then, take your magnet and hold it near the filings, on the outside of the test tube. Grab the filings and slide them up and down on the inside of your test tube!
Magnets are made when the particles that make up certain metals are aligned with the lines of magnetism that reach out around the Earth, from the North and South Poles. The particles that make up Iron, have this quality too, which is why iron is attracted to magnets!