This experiment is great in a time when household items are in shortage. With this experiment, all you need is tap water, a cup, salt and an egg or any plastic toy like a Lego piece.

This experiment will allow your child to ask questions.


  • Egg or a small piece of plastic, such as a Lego
  • Clear plastic cups, mason jars or clear glasses
  • Tap Water
  • Salt
  • 5 pieces of paper with numbers 1 through 5

Saltwater Density Setup

    1. Fill your 5 cups 2/3 full of warm water. For this experiment we used 5 cups, but you can use 2 or 3 cups. It depends on how much fun you want with this experiment.
    2. Let’s Add Salt and make sure its all dissolved
      • Cup 1 – No Salt
      • Cup 2 – Add 1 teaspoon of salt
      • Cup 3 – Add 2 teaspoon of salt
      • Cup 4 – Add 3 teaspoon of salt
      • Cup 5 – Add 4 teaspoon of salt
    3. Add 2 drops of food coloring to the water. We put different food coloring in each cup.
    4. Now let’s add the egg or a small piece of object in the cup.

The Science Behind the EGG!!!

The first egg sinks to the bottom of the glass of regular tap water. This is because a raw egg has a greater density than regular tap water. Essentially, the egg has more matter stuffed into a specific area (volume) than the same amount of water. When you add salt to the water, you increase the density. The more salt you add, the denser the water and you can see the yellow cup of water with 5 spoonfuls of salt the egg is floating on the top.

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