This science experiment is easy to do and requires few materials, all of which you probably already have on hand. It can be done with kids of any age. My preschoolers really enjoyed it, but it's suitable for older kids too.
We started by filling 3 glasses with equal amounts of water. One was cold water, one was cold water with salt and food coloring (just for fun), and one was warm water. The fourth we left empty.
We put an ice cube in each of the four glasses and made our hypothesis about which would melt first. My five year old guessed that the ice cube in warm water would melt first and the ice cube in the cold water would melt last.
|We had to do two salt water mixtures since we couldn't agree on just one color.|
The substances with the fastest moving particles melted the ice sooner than the substances with slower moving particles. When faster moving particles slam into slower ones, some of the energy is transferred, allowing the ice to become water.
- Warm water - The warm water has the fastest moving particles.
- Cold water - Slower moving particles than the warm water but still faster than salt water or air.
- Salt water - Adding salt to the water causes the temperature to drop, resulting in slower moving particles than plain water.
- Air - Because air is a gas, it has fewer particles to bump into the ice than the water does.
We also tested the melting rate when the water was stirred vs. not stirred.
The ice cube in the water that was stirred melted faster because stirring causes the molecules to collide at a more rapid rate.
They also did some experiments on their own:
What are your favorite science activities to do with your kids?
If you're looking for more science fun be sure to check out these 20 summer science ideas for kids: