What You’ll Need
- Small plastic jewels (or grapes, raw eggs or any small, dense item)
- Four clear cups of water
- 2 tablespoons of salt
- 2 tablespoons of sugar
- 2 tablespoons of baking soda
- Dissolve 2 tablespoons of salt in one cup, 2 tablespoons of sugar in another cup and 2 tablespoons of baking soda in the third cup. Leave one cup of plain, fresh water.
- Label each cup with its contents.
- What do you think will happen in each cup when you drop the jewels into the water?
- Drop the jewels in the water and see what happens!
What We Learned
- Salinity (the saltiness of water) is chemistry! Your tap water is also treated for quality and composition.
- Saltwater is denser than freshwater. Density is how much space a substance takes up in an object. In this case, it means that salt takes up space in the water it occupies.
- The objects in the baking soda mix should float because it contains a type of salt.
- There is more than one property in the baking soda that will produce carbon dioxide bubbles, causing the jewels to float in the middle of the mixture.