Stem Challenge: Fireworks in a Jar

The theme for Week 1 of our Summer Program was America the Beautiful! As we celebrate the end of the school year leading up to the Fourth of July, let’s make some fireworks in a jar for this week’s #CMMSSTEMChallenge. 

      • Clear jar or cup
      • Warm water
      • Vegetable or olive oil
      • Food coloring in several different colors
      • Small bowl 
      • Fork
      1. Fill your jar 3/4 of the way full with warm water.
      2. In a separate bowl, mix  3-4 tablespoons of oil and several drops of different colors of food coloring. You will need about 16 drops total of whatever colors you choose.
      3. Use a fork to gently mix the oil and food coloring together.
      4. Gently pour the oil mixture into the jar.
      5. Watch what happens—the food coloring will slowly sink out of the oil and into the water. When this happens, it will expand and begin to mix with the other colors to create “fireworks.”
The Science

Remember when we talked about density earlier in the year? Food coloring dissolves in water but not in oil. Because the oil is less dense than the water, it will float at the top.  Once poured into your jar, the colored droplets will begin to sink because they are heavier than the oil. Once they sink into the water, they will begin dissolving into the water (which looks like a tiny explosion).

Activity Credit: I Can Teach My Child