25 Easy Home Experiments for Science Fairs
Discover chemistry, physics and biology projects to dazzle in your presentation. Let's get to work!
Amazing Chemistry: Reactions at a Glance
1. Baking Soda and Vinegar Volcano
The classic of classics. Watch an acid-base reaction that releases carbon dioxide in a foam eruption that simulates a real volcano in a safe and spectacular way.
See Materials
- Small plastic bottle
- Sodium bicarbonate and vinegar
- Liquid soap and red dye
- Clay or modeling clay
2. Elephant Toothpaste
Creates an avalanche of giant foam that is warm to the touch. A visual lesson in catalysis and exothermic reactions that will surprise everyone with its speed and volume.
See Materials
- Plastic bottle
- Hydrogen peroxide (3% H Peroxide)
- Dry yeast and warm water
- Liquid soap and dye
3. Homemade Lava Lamp
A hypnotic spectacle of colorful bubbles rising and falling. It explores the concepts of density and polarity of liquids in a very visual and relaxing way.
See Materials
- Glass flask or bottle
- Water and vegetable oil
- Food coloring
- Effervescent tablets
4. Invisible Ink with Lemon
Become a spy and write secret messages that are only revealed with heat. Learn about oxidation reactions in a fun and mysterious way.
See Materials
- Lemon juice
- Cotton swab or brush
- White paper
- Heat source (bulb, with supervision)
5. Naked and bouncing egg
Dissolve an eggshell using vinegar and discover the semi-permeable membrane that remains. A fascinating experiment on chemical reactions and osmosis.
See Materials
- Raw egg
- White vinegar
- Large glass bottle
6. Homemade Sugar Crystals
Grow your own edible sugar geodes. A sweet lesson in patience and chemistry about supersaturated solutions and the crystallization process.
See Materials
- Sugar and water
- Glass flask
- Skewer stick or string
- Clothespin
Fascinating Physics: The World in Motion
7. Vinegar and Bicarbonate Rocket
Propulsive launch! Apply Newton's 3rd Law by building a rocket that is propelled by the pressure of the gas generated by the reaction of baking soda and vinegar.
See Materials
- Plastic bottle and cork
- Sodium bicarbonate and vinegar
- Paper napkin and ribbon
8. The Floating Egg
Discover the mystery of density by floating an egg in water. A simple and clear experiment that demonstrates how salinity affects the buoyancy of objects.
See Materials
- Raw egg and tall glass
- Water and table salt
- Spoon
9. Balloon Driven Car
An engineering challenge to understand propulsion and energy. Design and build a vehicle that moves with the force of air from a balloon. Let's race!
See Materials
- Balloon, straws and bottle caps
- Skewer sticks and cardboard
- Adhesive tape
10. The Egg in the Bottle
Watch how atmospheric pressure sucks a boiled egg into a bottle. A mind-blowing demonstration of an invisible but very powerful physical concept.
See Materials
- Peeled hard-boiled egg
- Glass bottle with wide mouth
- Matches or paper (with supervision)
11. Spaghetti Bridge
Can something so fragile support weight? Of course! Learn about force distribution, tension and compression in this structural engineering challenge.
See Materials
- Dried spaghetti
- Hot glue or glue gun
- Books or objects to test resistance
12. Tornado in a Bottle
Creates a fascinating water vortex that mimics a tornado. A perfect visualization of centripetal force and fluid dynamics in action.
See Materials
- Two 2L plastic bottles
- Water
- Strong adhesive tape or connector
Biology and Life Sciences
13. Extraction of DNA from a Strawberry
Observe the code of life! With homemade materials you can break the cells of a strawberry and extract its DNA, which will appear as a whitish, stringy substance.
See Materials
- Strawberries, salt and liquid soap
- Isopropyl alcohol (very cold)
- Airtight bag, strainer and glasses
14. Flowers that Change Color
A beautiful experiment demonstrating capillary action. Watch how white flowers absorb colored water and dye their petals, showing how plants are nourished.
See Materials
- White flowers (carnations, daisies)
- Glasses, water and dyes
15. Germination in a Bag
Watch the miracle of life up close. Follow the growth of the root and stem of a seed day by day, without the need for soil, in a direct window into the cycle of life.
See Materials
- Plastic bag with zipper
- Large seed (bean, lentil)
- Paper towel and water
Optics and Energy: The Magic of Light
16. Rainbow in a Glass
Create your own rainbow without rain. Demonstrate refraction and how white light separates into all the colors of the spectrum as it passes through water.
See Materials
- Glass with water
- Sheet of white paper
- Solar light or powerful flashlight
17. Solar Oven with Pizza Box
Cook with the sun! Build an oven that uses renewable energy to heat food, learning about the greenhouse effect, reflection and heat absorption.
See Materials
- Empty pizza box
- Aluminum foil and plastic kitchen wrap
- Black construction paper and tape
18. Homemade Camera Obscura
Build a simple version of the first camera and see an inverted image of the world. The basics of photography and optics in a simple box.
See Materials
- Cardboard box
- Aluminum foil and vegetable foil
- Black adhesive tape and a pin
More Creative and Popular Ideas
19. Battery with Potatoes or Lemons
Generate electricity with a potato. An amazing introduction to circuits and batteries, creating an electrochemical reaction to light an LED.
See Materials
- Potato or lemon
- Galvanized nails and copper coins
- Cables with clamps and an LED
20. Magnetic Slime
A slime that you can control with a magnet, as if it were alive! Explore magnetism and non-Newtonian fluids in an incredibly tactile way.
See Materials
- School glue, liquid starch or borax
- Iron powder
- Neodymium magnet (powerful)
21. Single Homopolar Motor
Build the world's easiest motor in less than a minute. Demonstrate the Lorentz force and how electricity and magnetism create motion.
See Materials
- AA battery
- Neodymium magnet
- Copper wire
22. pH Indicator with Red cabbage
Colorful chemistry! Use the juice of this cabbage as a natural pH indicator that changes color according to the acidity or alkalinity of the substances.
See Materials
- Red cabbage leaves
- Pot, water and strainer
- Liquids to test (lemon, baking soda...)
23. Levitating with Static Electricity
Make small plastic or paper objects levitate and dance in the air using only a balloon. The most fun way to experiment with electrostatics.
See Materials
- Balloon
- Your own hair
- Small pieces of tissue paper or plastic
24. Magic Hydrophobic Sand
The sand that doesn't get wet! Transforms ordinary sand into a material that repels water in an amazing way. Great for explaining material properties and surface tension.
See Materials
- Fine dry sand
- Waterproofing spray (for shoes/textiles)
- Container with water
25. Hypnotic Wave Pendulum
Create a visually fascinating installation that demonstrates how pendulums of different lengths create dancing wave patterns. Physics and art in one.
See Materials
- Wooden board and hooks
- Thin thread or rope
- Nuts or washers (weights)
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