How many layers of the Atmosphere are there?

How do candles use wax as fuel? What is smoke made of?

What do you need in order to turn water from liquid to solid?

Do cocoa powder and milk like each other?

Is there really metal in your food? Can you extract it?

Which is denser: saltwater or sugar-water?

How much water does it take to make snow?

Can we make frost on the outside of a can?