On 17/08/2012 17:52, Andrew Gabriel wrote:
Actually, looking
back, our chemistry teachers allowed us to do some quite risky
things like dropping sodium into acid (by a remote control scheme
we had to build for the purpose). That was really spectacular,
and we could see why the text books all say to never do this.

Ah, yes. I remember one teacher showing us about phosphorus and sodium,
and how you store the former in a jar of water, and the latter in a jar
of oil, "...and make sure you never get them muddled up! ha ha!" and
then proceeded to do precisely that, topping up the sodium jar from the
tap...

"RUN!!!"

Fortunately no injury or major damage resulted.

David