Egg Floats in Salt Water
Egg sinks in one and floats in the other.
Teaching & key ideas
What you do: Put egg in fresh water then concentrated salt water.
What students see: Egg sinks in one and floats in the other.
Why it works: Dissolved salt increases water density and buoyant force.
Question to ask: Did the egg change—or the water?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Did the egg change—or the water?