Question: What makes popcorn pop?

Jess Bean answered on 18 Jun 2013:

I wasn’t sure about this so I had a little look on the NASA website to check I was correct (I kinda was!) – http://www.nasa.gov/audience/forkids/home/popcorn.html

The short answer is that it’s because you are heating up the water inside the corn. When you heat the water it becomes steam and ‘pops’ out of it’s little casing. Microwaves work by ‘heating up’ water molecules (the water molecules are actually ‘excited’ to a higher energy level), so this is why you can make popcorn in the microwave. If you’ve ever microwaved baked beans for too long (you’ll understand this if you ever become a university student!), the beans can ‘pop’/explode as well, though it’s more messy!