As a scientist, it is super important to make observations and ask questions.
With this experiment, we can observe how and why substances float or sink in water!
Materials:
Table salt, two clear drinking glasses, a spoon, tap water, food coloring
Time Estimated:
10 minutes
Directions:
In Cup A, only add warm water.
In Cup B, add a few teaspoons of salt.
Then, add warm water and stir until all of the salt is dissolved!
Grab your food coloring and place a few drops into Cup A. Record your observations.
Add in a few drops to the saltwater solution in Cup B. Record your observations.
Do you notice anything different about how the dye was dispersed in each of the cups? Look over your recorded notes and compare the two observations!
Think Like A Scientist:
What is density?
What other substances do you think will float in water?
How It Works:
When you mix the two types of water you made in this experiment, the tap water with the food coloring moves to the top of the salty tap water because the saltwater is heavier than the regular tap water. This is because of something called density. Density is the weight of something, or how heavy it is, based on the amount of “stuff” (or molecules) inside of it that is packed into a certain volume, or a certain amount of space. When we add salt to the water, it increases the amount of “stuff” in the water in the same amount of space, so the saltwater becomes “heavier” and has a greater density. The water with the food coloring is not as heavy as the saltwater because there is no added weight in it, so it will sit on top of the heavier saltwater.
Looking for more fun at home STEM activities for your young scientist? Check out our workbook full of exciting science experiments and empowering activities!
