Cool Bombs
Game on reversible and irreversible changes
http://www.sciencekids.co.nz/gamesactivities/reversiblechanges.html
Thunder Crackers
Facts about Thunder http://www.sciencekids.co.nz/sciencefacts/weather/thunder.html
How to make the Thundercrackers – http://ithinklaingholm.blogspot.co.nz/2013/11/paper-banger.html