One thing that you can make easily for your project is a simple homemade lava lamp. This project is not only fun and visually appealing, but it also helps you understand the concept of density and how oil and water do not mix. Here's how you can create your own lava lamp:

Materials Needed:
- A clear plastic bottle with a screw-on lid
- Water
- Vegetable oil
- Food coloring
- Alka-Seltzer tablets

Creating the Lava Lamp:

1. **Prepare the bottle**: Start by cleaning and drying the plastic bottle thoroughly. Make sure the bottle is transparent, as this will allow you to see the colorful "lava" inside.

2. **Fill the bottle**: Fill the bottle about three-fourths full with vegetable oil. Leave some space at the top to allow for bubbling later on.

3. **Add water**: Slowly pour water into the bottle, filling it almost to the top. Leave a small gap to prevent overflow when you add the Alka-Seltzer tablet.

4. **Add food coloring**: Choose a color of food coloring you like and add a few drops to the water in the bottle. The food coloring will mix with the water but not with the oil, creating a vibrant and colorful effect.

5. **Break the Alka-Seltzer tablet**: Break an Alka-Seltzer tablet into smaller pieces. You can use half or a quarter of a tablet to start with.

6. **Drop the tablet**: Drop the broken pieces of Alka-Seltzer tablet into the bottle and quickly screw the lid on tightly.

7. **Watch the lava lamp in action**: As the Alka-Seltzer reacts with the water, it creates gas bubbles that rise to the top, carrying some water with them. When the bubbles reach the top, they burst, and the water falls back down through the oil, creating a lava lamp-like effect.

8. **Repeat the process**: If you want to continue the lava lamp effect, you can add more pieces of Alka-Seltzer tablet as needed.

By following these steps, you can create a fascinating homemade lava lamp using simple household items. It's a great way to learn about density and chemical reactions while having fun with your project.