A lot of candy bars look the same but are very different! Can we explore these differences using water?
Something to hold water- this can be your sink, bathtub, a plastic bin, or anything so long as it can fit your candy bars. Clear containers help but aren't necessary.
Different candy bars that are the same size (I like Milky Way, Twix, Snickers, and 3 Musketeers in "fun size")
Optional scale, rulers, and other measuring tools
Fill your container with water.
Open each candy bar but don't eat them!!
Looking at each candy, make a prediction or guess as to whether or not it will float in the water. You may wish to weigh or measure the candy bars to help you make your guesses.
One at a time place each unwrapped candy bar in the water and watch what happens. Were you surprised?
Cut each candy bar in half and compare them. Do some have lighter fillings than others? Do some have more air in them?
Reflect on this activity and extend it:
Try placing the halved candy bars in the water, do they act differently than a whole candy bar?
Try exploring different types of candy like gummy candies or hard candies.
Try exploring different sized candy bars. Do the same types of candy bars behave differently when they are different sizes?
With this investigation, we are exploring density. Density is the measure of how much stuff something has in it for its size. Scientists would call that the amount of matter in a given volume. The different candy bars are the same size but have different amounts of stuff in them and so have different densities. This means that they behave differently in water as some will float (and have a density less than water) and some will sink (and have a density more than water).
You can download a printer-friendly version of this activity below!