Chemistry lab, weaponry of the
Magnesium ribbon - a favourite. Produces an intense white light when lit. Can cause temporary blindness if let off in someone's face.
Sodium - produces unimpressive fizzing display when dropped in a sink full of water unless you've got enough to simulate Krakatoa. Dunking a head in the fizz will cause extreme panic and some flailing.
Phosphorus - the heavyweight. Ignites on contact with the air! Imagine sticking it down someone's collar!
Master these three and you may move on to caesium, if you can get the key to the special cupboard.
written by Co*or Fr*nklin, approved by Log

Another battle tested chem-lab weapon was a DIY cattle-brand made by heating up a test tube holder until it was glowing hot and then pressing the prongs down on a classmates books, pencil case, tie, blazer etc, leaving a livid black imprint. Livid!
written by ch*mi*al h*zard, approved by Susan

Here's one we learned from experience: copper sulphate, when flung into someone's eye from across the room, causes a club sandwich triple of hilarity;
1. The victim's agony is most immediately and most obviously hilarious.
2. The classroom will be left alone for forty minutes while the teacher runs around, hoping to bump into a paramedic. This allowed for simple unnattended paper-plane throwing hilarity.
3. The next day, the victim comes into school like a jazzy panda with an orange eye, which is of course funny in itself, but will be rendered hilarious when he kicks the crimson shit out of his tormentor.
When this happened in our class, hilarity just didn't stop ensuing.
written by Bl*rt *nart, approved by Log

Our science teacher once gave us a demonstration of what happens when you reverse the motor in a vacuum cleaner. We soon discovered that the best use for this device was to fire red-hot boiling tubes at unsuspecting students.
written by an*nymou* use*, approved by Ponky

That pales into insignifigance next to the mini-ELO stage show that is opening all the gas taps around a square workstation and lighting them. With just a snaffled pack of Swan Vestas the entire classroom can look like a Bonnie Tyler video.
written by Dr*w St*le*, approved by Conor

Apparatus: Chlorine gas, a 'Griffin Savers' school bag and Richard Savage's head.
Method: Combine.
Conclusion: With his head bagged, Richard is both dead and alive according to quantum law; in a superposition of states. It is only when Creedy removes the bag and sees that although Richard WANTED to die during the experiment, he is in fact alive - that the superposition is lost.
written by To*y *re*n, approved by Rosy