In this activity, students investigate water density by floating eggs in freshwater and saltwater.
By the end of this activity, students should be able to:
- discuss the concept of density
- discuss how salt increases the density of water
- explain why an egg sinks in freshwater but floats when salt is added.
Download the Word file for:
- introduction/background notes
- what you need
- what to do
- extension idea.
Explore the big ideas that underpin floating and sinking in the article Building Science Concepts: Floating and sinking.
Temperature, salinity and water density – use this activity to help your students visualise differences in water density.
Buoyancy in water – students make a Cartesian diver to demonstrate the relationship between volume, mass and density.
Investigating seawater – students investigate some of the properties of seawater.