Potassium + Water
We had a substitute/trainee teacher for one of our lessons where we learned about chemical reactions. The other teachers let him get on with it, watching with fatalistic amusement from the back of the room....

He set up the stuff properly...the bowl of water, the protective screen, and his good self with the goggles. The fascinated students sit behind the screen watching as, with great drama, he drops a tiny piece of potassium in the water.

Nothing.

Absolustely nothing. Students start laughing. Teacher looks a little put out, and disappears into the cupboard. He returns with a massive chunk of the stuff and puts it in the water where it ...

...

EXPLODES!!

The screen cracks, and the ceiling has cracks radiating across from the bits of bowl embedded in it. There's water everywhere, including over the soaked and frazzled looking teacher. The screams from the more nervous kids are made hilarious by the fact that the entire science department is standing at the back of the room, crying with laughter, at this sub teacher who stands, tongs still outreached...

Probably one of many explosion stories this week.
(Sivvus trolley collision in the fruit aisle led to a jam, Thu 17 Mar 2011, 14:45, 3 replies)

Did you go to MUS?
Seriously....I was THERE!
(Galahad is out of his gourd on yellow bentines, Thu 17 Mar 2011, 14:49, closed)

Nah, this was RHMS
But I reckon something similar's happened at most schools. It's like a gauntlet run for trainees.
(Sivvus trolley collision in the fruit aisle led to a jam, Thu 17 Mar 2011, 14:52, closed)

you dont know man
YOU WERENT THERE...
(Bonzodog29 is an unemployed sponge of the worst kind, Thu 17 Mar 2011, 14:53, closed)