In its most basic form, preschool students can complete this activity, but it can be a worthwhile experience for elementary students and can be made a bit more challenging for middle school students.
Provide students with an assortment of objects (make sure some float and some sink - some good floaters are aluminum foil, ping pong balls, candles, eye droppers).
Students hypothesize which objects will float and which will sink. Older students can write down their hypothesis, while younger students can simply divide the objects into two piles.
Students then test the objects in a tub of water.
Older students could be challenged to calculate the actual density of each object.
