1. erupting volcano: Create a volcanic eruption using baking soda and vinegar. It’s a classic experiment that never fails to impress!

2. solar oven: Teach your students about solar energy by building a simple solar oven using a pizza box and aluminum foil.

3. lemon battery: Show how fruits can produce electricity by making a battery out of a lemon, some copper wire, and a zinc-coated nail.

4. static electricity: Demonstrate static electricity using balloons and different materials like wool or hair.

5. water cycle in a bag: Create a mini water cycle in a bag using water, a ziplock bag, and a sunny spot.

6. density tower: Explore the concept of density by layering liquids with different densities, like oil, water, and syrup.

7. homemade lava lamp: Make a lava lamp using oil, water, food coloring, and effervescent tablets.

8. growing crystals: Grow your own crystals using borax or table salt and hot water.

9. egg drop challenge: Encourage students to design and build a contraption that can protect an egg from breaking when dropped from a height.

10. rainbow milk: Explore surface tension and chemical reactions by adding food coloring to milk and adding drops of dish soap.

11. balloon rocket: Create a balloon-powered rocket using a balloon, string, and a straw.

12. seed germination: Investigate how plants grow by germinating seeds in different conditions, such as light versus dark or wet versus dry.

13. mold bread experiment: Observe how bread develops mold by placing slices of bread in different environments, like the fridge, a plastic bag, or out in the open.

14. sink or float: Test the buoyancy of various objects by predicting and observing whether they sink or float in water.

15. homemade slime: Engage students in a hands-on experiment by making slime using glue, borax, and water.

With these 15 impressive science experiments and activities, your fourth-grade students will have a blast while learning important scientific concepts. Don’t forget to emphasize the scientific method and encourage students to make observations, ask questions, and draw conclusions from their experiments. Happy experimenting!