Decade's Best Chemistry Projects

You knew some sort of fire project would be listed first, right? This smoke bomb project is extremely easy, plus it only takes two ingredients... potassium nitrate and sugar. If you can't find the potassium nitrate, you can make it yourself.

The smoke bomb tutorial was the top project on the site for years, but the video showing how to make your own green fire took its place in terms of reader popularity. I'm extremely fond of this project, too. The green fire is fun to make by itself, plus it can be applied to other projects (e.g., green fire jack-o-lantern, burning ice cubes with green fire).

This density column is made using colored sugar and water so it is safe for kids to make, plus it's simply very pretty.

All of the crystal projects have been popular, but this borax crystal snowflake has been a favorite ever since it was posted. I think it's partly that the crystals grow overnight and are safe to touch. I use these crystal snowflakes as sparkling holiday decorations.

This is your typical slime recipe. The claim to fame for this recipe is that it produces a slime that resembles... well... snot (if you have a serious sinus infection). Is it gross? Yes, which I'm pretty sure is the point.

Sugar crystals take about a week to grow, so this is not an instant-gratification project, but the resulting rock candy is edible so it's worth the wait. This tutorial is available as step-by-step written instructions, as a video, or with tips for avoiding common problems.

This project is popular in part because it teaches about freezing point depression in a fun way and in part because it's a really easy way for anyone to make good ice cream. This is the easiest way to make ice cream yourself!

I used cabbage juice and a coffee filter to make this homemade pH paper to test the acidity of common household chemicals, but you could use any of the home and garden pH indicators to make pH paper. If you don't have a cabbage, try using cherries, blueberries, or rose petals.

You've made a classic baking soda and vinegar volcano, right? If not, there's no time like the present to give it a try. You can get deeply-colored lava if you mix food coloring or powdered drink mix in with the vinegar used to start the eruption.

This rechargeable 'lava lamp' uses carbon dioxide bubbles to swirl colored globules around inside a plastic bottle. It's a kid-friendly chemistry toy that can be used to demonstrate several chemistry principles.