1. Baking Soda Volcano: Create a mini volcanic eruption using baking soda, vinegar, and food coloring. This is a classic experiment that teaches kids about chemical reactions.
2. Static Electricity with Balloons: Rub balloons against different materials like hair or wool and watch them stick to walls or attract small objects. This experiment helps explain the concept of static electricity.
3. Egg in a Bottle: Place a peeled hard-boiled egg on top of a bottle with a small opening, then watch it get sucked into the bottle. This demonstrates the power of air pressure.
4. Rainbow Milk: Pour milk into a shallow dish, add a few drops of different food coloring, and then dip a cotton swab in dish soap. Observe as the colors swirl and create a mesmerizing pattern. This experiment explores surface tension and the interaction between substances.
5. Homemade Slime: Mix together glue and borax solution to create a slimy, stretchy substance that kids love to play with. This experiment delves into polymer chains and material science.
6. Walking Water: Set up cups filled with colored water and connect them with paper towels. Observe as the water climbs up the paper towels, defying gravity. This experiment introduces capillary action and absorption.
7. Invisible Ink: Use lemon juice or milk as an invisible ink and reveal the hidden messages by heating the paper. This experiment explores the concept of chemical reactions and oxidation.
8. Solar Oven: Construct a simple solar oven using a pizza box, aluminum foil, and plastic wrap. Place food inside and let the sun’s heat cook it. This experiment demonstrates the power of solar energy.
9. Fruit Battery: Use pieces of different fruits, like oranges or lemons, as electrodes to power a small LED light bulb. This experiment showcases the principles of electricity and conductivity.
10. Rainbow in a Jar: Layer different liquids with varying densities, such as honey, oil, water, and food coloring, in a transparent container. Watch as they form distinct layers, resembling a rainbow. This experiment teaches kids about density and liquid properties.
11. Mentos and Soda Explosion: Drop Mentos candies into a bottle of soda and observe a foamy eruption. This experiment explores the reaction between carbon dioxide gas and Mentos candies.
12. Soda Can Implosion: Heat up a small amount of water in a soda can, then quickly flip it upside down into a container of cold water. Witness the can collapse due to the rapid change in pressure. This experiment demonstrates the concept of thermal expansion and contraction.
13. Magnetic Slime: Combine glue, iron oxide powder, and liquid starch to create a slime that reacts to magnets. This experiment explores the properties of magnetic fields and how they interact with certain materials.
14. Food Coloring and Water Density Tower: Layer different colors of water with varying sugar concentrations to create a colorful density tower. This experiment investigates the concept of density and solubility.
15. Balloon Rocket: Inflate a balloon and attach it to a string stretched between two points. Release the open end of the balloon and watch as it propels forward. This experiment illustrates Newton’s third law of motion and the concept of thrust.

These 15 fourth-grade science experiments and activities provide hands-on learning experiences that are both educational and enjoyable for kids. Have fun exploring the wonderful world of science with these engaging projects!