MadSci Network: Chemistry |
It is a chemical change in the case of Jell-O and a physical change in the case of popcorn. In the case of popcorn, steam pressure builds up inside of the kernel as it is heated and eventually ruptures the outer shell of the corn. So it is basically a physical change. In the case of Jell-O, the protein forms a network and water gets trapped in the network. The unfolding and networking of proteins can be seen as chemical or physical changes, even though perhaps one can think of it also as a physical change. -MVK
Try the links in the MadSci Library for more information on Chemistry.