Well, my class has done a few stupid things (maybe not exactly nerdy or blonde, but oh well). For example, in Chemistry alone we have had:
1. Mercury spilt all over the floor (one guy was holding the bottle and decided that you would see it better if the bottle was upside down- unfortunately the glass stopper came out, along with about half the mercury)
2. Possibly poisonous gas: we'd gone and done indicator testing with a whole lot of things-of course choosing stuff we thought would be quite potent- and a couple of the guys decided to put everything together and see what happened. Apparently it smelt like pool chlorine and produced a burning feeling.
3. We were doing something basic with bunsens, but there were some transformers left out from a previous prac. One guy decided to light his bunsen with electricity intead of matches, so he was standing there for 30 seconds to a minute with the gas running while trying to light the thing by sparking some wires over it. Unfortunately for him our teacher came in, saw what was happening and went right off at him.
And no, I'm not the guy who did these things.
Sodium offered some good opportunities for mistakes too, but I'm not saying how.