Today we are going to talk about icebergs, and in the process, learn about density.
What you'll need for this experiment:
- A container or large bowl, something that you can see through, filled up with a couple inches of water
Take one of your balloons and fill it up with water. You want it to measure a few inches in diameter. Stick it in the freezer and wait until it's completely frozen. This is going to represent our iceberg. Next, take a pair of scissors and cut the balloon away from the chunk of ice. Be careful when doing this part, sharp scissors help.
When water freezes into ice, it becomes slightly less dense compared to water in its liquid form. This is a good teachable moment to pause and ask, 'if we know that ice is a little bit less dense than liquid water, what do you think will happen when we drop the ice into the water?' Now, drop the iceberg into the water and watch what happens.
Just like an iceberg floating in the ocean, about 90% of the ice chunk is below the surface of the water and about 10% is above the surface of the water. The reason that this experiment works is because ice is slightly less dense than water, and that allows the ice to float.
It's similar to when you make yourself a drink, and the ice floats to the top! Now you know it's because of density!