C'mon then - lab experiments that went wrong, disasters, fights etc
What was the funniest thing to happen to you at school?
Matches to gas taps for instant flame thrower?
Bunsen burner fountain?
Chemistry worksheets in desk blaze?
Swot trapped on roof during roof during French?
Very small but not technically dwarf boy locked in stationery cupboard for entire lessons.
He loved it really...
Best friend farted very loudly in gym during a silent performance of handstands in front of the whole year, and blamed it on the mat rubbing against the wooden floor. Sadly, he was nowhere near the mat at the time.
Mad science teacher with palsy would put his gammy hand in acid just to freak out the new kids.
I once evacuated the science building cos I pierced an areosole can in my gym bag. It spray stuff everywhere and people thought there was osme kind of toxic gas. The firemen were called in. Lucky it was before 9/11 or I would have been shot 
I hope no one here went to Columbine...
Once our PE teacher climbed on the school roof to throw down all the balls etc that had got stuck on it and some cheeky chappies nicked his ladder.
It was really funny seeing him red in the face and shouting but unable to get down from the roof.
A teacher once clawed one of my mates down the face, he was a cheeky bastard a totally deserved it!
One of our teachers - this is anecdotal, from quite a few years before I started - set fire to her hair when demonstrating what not to do with a Bunsen burner.
And yes, she was (or at least became) head of the Maths, Science and Technology Department.
We had a French lesson where the teacher had to pop out and in the short time he was out mock trenches made up of up turned desks were constructed at either end of the room and paper warfare ensued.
Mr Spooner (born 1st April) was not best pleased on his return.
All I remember of chemistry lessons myself, if playing with Bunsen burners, chewing flints, doodling in my book, and talking about porn with the teacher.
French, just drawing in my exercise book and generally joking about with friends. Oh, and discussing Family Guy with the teacher.
The library, however, was immense fun...
I had my own chair, with my name on it, in the headmaster’s office. I was a very ruley young lady. My poor parents despaired.
I was a horrible brat. Each teacher got given a different Charley. My English teacher was cross eyed so I pretended I was. I had the crosses eyes ever crossed ever.
My Geography teacher was a very Hairy Mary & we nicknamed her Werewolf. Poor cow would have me howling in her lessons etc. I had a pre-prepared forged note, from my parents, informing her of my medical condition. (A form of tourettes). My History teacher suffered from Alopecia. I would buy fake hair & leave it all around the classroom for her to find & think it was hers. My PE teacher had a very squeaky voice. So I pretended to have a twitch, like a mouse. (Same forged note. (A form of tourettes).
Anyhoo on one of the very, very rare occasions I did partake in assembly, (I skived like a bastard) I would have to twitch like a mouse, roll my eyes into the corner & howl. One particular time the teachers thought I was fitting, due to choking on Poor Alopecia Misses hair. An ambulance was called to the school & I was taken to hospital. Where they discovered the only thing wrong with me, was that I was pregnant.
Me and my mates once turned up 49 minutes late for a 50 minute lesson. We just said 'sorry we're late' and sat down. Got detention but i always got detention
Me and my best friend at school hated cross country running. The good thing about it though was it took place in the wood near my house so we would trail along for about 20 mins, getting muddy, slacking behind as us fatties did then when the other were just out of view, we would make our way though a short cut through some bushes that took us just across from my house. Since my folks weren't in, we would go in, watch a bit of tv and eat biscuits with squash then make our way across the old playing field, through a broken fence, and leg it back to the school, where everyone else had gathered and were waiting for us to "finish". Because we lagged behind so much in PE anyway, no one guessed. But my mum always had a go at my Dad for eating all the hob nobs.
Why doesn't that surprise me about Charley?
I remember one teacher giving me 6 of the best with a cricket bat. Didn't harm me though - oh no!
That's what children need today! Some good old fashioned capital punishment.
Charley, you're just plain cruel.
And Adam, ever get a Saturday detention?
One thing that makes me laugh to this day (and is useable), is in class, no matter what time of year, my mate Joe could say "It's snowing!" and get the whole class to nearly break their neck to look at the nearest window.