Re: Why does popcorn pops?

Hello, i hope you can answer my question.
I've been looking the answer everywhere but can't find it.

I know it's something about the preassure and heat, but I'm not sure

Yes, the answer does have to do with pressure and heat. The heat causes the 
water in the middle of the popcorn kernel to turn into steam. At typical 
pressures (atmospheric pressure) the amount of water in the kernel would be many 
times the size of the kernel, but the outer part of the kernel hull holds it in 
and the pressure climbs higher and higher. Finally the pressure is greater than 
the hull can stand and the superheated steam blows open the kernel and expands 
the middle portion.

When you get into high school chemistry you will learn about the Universal Gas 
Law which says that when you keep a gas at the same volume that the pressure 
rises the same amount for each degree of temperature increase. It also says 
other things, but that is the part relates directly to you question.

Thanks for popping the question,
David Winsemius.