Science experiments from hell

Ok 1. Do not attempt to recreate anything posted that could be potentially dangerous to yourself or others. Not that you would be that silly
______________________________________________________________

Rito! with that out the way, have any of you ever heard of, or done, anything really really "fun" aka probably stupid in a science lesson?

Like say, my brother, who definately "didnt" take a large amount of potassium and place it inside a pineapple.

Or myself who "didnt" put a teaspoon of salt in already-boiling water, causing an explosion like effect. The incident wasnt forgotten and i was remembered as the one who managed to explode water on his first ever science lesson. aaahhh.....memories.....

So what about you guys?