Originally Posted by Just Passin' By
Schools aren't keeping the makings of chemical warheads out for easy access and, if they are, the school is the problem. There's not sufficient justification for the punishment in the story.
You can create an explosion from common stuff you probably have right now in your garage or under your sink. For a kid to try that stuff at school is beyond stupid and potentially, quite dangerous. It would be pretty stupid of the school to simply shrug it off.