In the apple sink or float experiment, we learned that whole apples do float (sorry for the spoiler!). Apples float because they are 25% air.
But do all parts of the apple float? Let’s find out in this density of apple parts experiment!
Before you conduct this experiment, I highly recommend you jump over to the parts of an apple activity to first study the different components of an apple. Since you have to cut open an apple anyway and separate out its parts, you might as well hit both fun apple-themed activities at once!
Density of Apple Parts
- An apple
- Knife (adults only!)
- 5 clear cups
- Free density of apple parts worksheet
1. Carefully cut the apple into different parts (stem, flesh, core, seeds, and skin).
2. Fill the cups about ¾ full with water.
3. Make a prediction: Do each of the apple parts float or sink?
4. Drop each part of the apple in separate cups.
4. Observe which parts float and which ones sink.
Where your kids surprised at the results? My son was! He thought because the whole apple floated, all parts of the apple should float. He recorded his predictions in the free worksheet and was shocked that he only got 3 out of 5 right!
I took this opportunity to explain to him that things may be more complicated than they seem. For example, a pebble would sink in water, while an empty bottle of water would float. But if you put the pebble in the bottle, then both would float as long as the pebble is not too heavy.
Similarly, the stem and the seeds make up a small portion of the apple. Therefore, the part that makes the apple float (the flesh) was able to keep the entire apple afloat despite the denser parts of the apple.
If you like this simple apple-themed STEM activity, make sure you check out: