Challange #1 Bouncy egg
Take an egg and a cup of vinegar. Soak the egg in the cup for about a day and the next day pick it up and see how is it different!
Pour 1/2 cup hydrogen peroxide solution, 1/4 cup dishwashing soap, and a few drops of food coloring into the bottle. Swish the bottle around to mix the ingredients. Set the bottle in a sink or outdoors or some other place where you won't mind getting wet foam everywhere.
In a separate container, mix a packet of active yeast with a little warm water. Give the yeast about five minutes to activate before proceeding to the next step.
When you are ready to do the demo, pour the yeast mixture into the bottle. The reaction occurs immediately upon the addition of the yeast.
Challange #2 Elephant Toothpaste
Challange #3 Lava Lamp
Fill the flask most of the way with your choice of oil. Fill the rest of the flask with water. The oil floats and the water sinks to the bottom of the jar under the oil and looks like little, clear blobs. Add a few drops of food coloring; your choice of color. The food coloring is water-based, so it will also sink and color the water that is now at the bottom of the flask. Break an Alka-Seltzer tablet into a few small pieces and drop them in the flask one at a time. Watch your lava lamp erupt into activity! As the chemical reaction slows down, simply add more Alka-Seltzer.