Today we’re going to be focusing on oceans. As you may know, water makes up about 71% of the earth’s surface, and about 97% of that is made up of saltwater from the oceans! Let’s do an experiment about the density of saltwater, and then make our very own salt dough starfish!
Materials:
2 clear cups/glasses of water, Small items to test density (fruit, raw eggs, almonds, etc.) and salt
Time Estimated:
10-15 minutes
Directions:
First, take two glasses and fill them with water.
Add salt to one of the glasses until the water is cloudy.
Stir in the salt.
Next, add a small item to test the density of both glasses. You can use small fruits, raw eggs, or whatever you have at home for this step!
Observe what happens to each glass.
Think Like A Scientist:
What happened to the small items in the regular water? What happened to the small items in the saltwater?
Did they have different reactions? Why?
How does the reaction in saltwater apply to water in the ocean?
How It Works:
This experiment looks at how salt affects ocean waters. Notice how the small objects in the regular water sink to the bottom, and how the objects in the saltwater float. This is similar to what happens with ocean water. The added salt makes water in the ocean denser, which makes it easier for things to float! Wasn’t that such a cool experiment? Isn’t it crazy how much salt can affect the density of water? Now we are going to do a cool art project using salt!
Salt Dough Starfish
Materials:
Flour, Salt, Water, Pencil, Bowl, Spoon or something to stir with, and Paints (optional)
Directions:
First off, mix together 2 cups of flour, 2 cups of salt, and 1 cup of water in a bowl.
Knead the dough together until it is soft.
Then grab a ball of dough and slowly mold it into a starfish by creating a middle section and then five little legs.
Next, you can use a pencil to decorate the starfish to make them look more realistic!
Finally, once you’re happy with them, you can either let them dry out over the next few days or you can pop them in the oven at 325 degrees for up to 3 hours, (with adult supervision) depending on how big you made your starfish.
Once they are dry, you could even go ahead and paint them!
Starfish are special creatures that need saltwater to survive. They cannot live in freshwater, so we need our oceans to keep them alive! We hope you enjoyed these experiments, feel free to check out more on the Boundless Brilliance YouTube channel!
Looking for more fun at home STEM activities for your young scientist? Check out our workbook full of exciting science experiments and empowering activities!
