I have always wanted to do the hydrogen gas/oxygen gas balloon explosion in class, but it isn't very practical or very safe. Once again Steve Spangler shows a much easier and safer way to do the reaction. Of course I had to try it myself and it works beautifully. Making the egg hollow is quite easy as shown here. The most common chemical reaction taught to middle school students is 2H2 + O2 ----> 2H2O. They rarely see it live though. They also have a hard time understanding that water gas is produced by this explosive exothermic reaction (the same chemical reaction that is used in the space shuttle main engines).