Elephant Toothpaste
This experiment creates a huge, foamy fountain that looks like a giant tube of toothpaste just exploded!
What you need:
- an empty 16 oz plastic bottle
- ½ cup of hydrogen peroxide
- 1 packet of dry yeast (mixed with 3 tbsp of warm water)
- a big squirt of dish soap
- different colors of food coloring
How to do it:
1. Prep the bottle: Place your bottle on a tray or in the grass. Pour in the hydrogen peroxide, add food coloring, and a big squirt of soap. Swish it gently.
2. Activate the Helper: In a small cup, stir the yeast and warm water until it’s smooth.
3. Pour the yeast mixture into the bottle and step back!
The Science:
Hydrogen peroxide is made of water and oxygen. Normally, the oxygen stays trapped inside. But the yeast acts like a catalyst (helper) that speeds things up. It kicks the oxygen out so fast that it gets trapped in the soap, making millions of bubbles. This is called an exothermic reaction. “Exo” means exit, and “thermic” means heat. So, the heat is exiting the bottle. If you feel the bottle, it will be nice and warm!
Build a Solar Oven
With this experiment, you are essentially using a box to trap the sun’s solar energy and turn it into heat to make your favorite treat, like s’mores!
What you need:
- a pizza box
- aluminum foil
- plastic wrap
- black construction paper
- a stick or ruler
How to do it:
1. Cut a three-sided flap into the lid of the pizza box and fold it back so it stands up.
2. Cover the inside of the flap with smooth aluminum foil (this acts as a mirror to reflect sunlight into the box).
3. Tape a double layer of plastic wrap over the opening you just made in the lid to create an airtight window.
4. Line the bottom of the box with black construction paper (black absorbs heat better than any other color).
The Science:
Reflection bounces the sun’s rays into the box. Absorption happens when the black paper turns that light into heat. Insulation occurs because the plastic wrap traps the heat inside. By using the stick to prop up the foil flap, you can align your solar oven to catch the most sun possible. Try it out on a very sunny, hot day!
