It's the most reactive element but Fluorine has long been one of the weaker films on The Periodic Table of Videos.
However we're gradually updating and improving all our element videos - and this week it was Fluorine's turn.
First up, here's the new version:
Fluorine is so reactive that very few chemists are equipped to handle it.
So we left our usual base (at the University of Nottingham, of course) and visited a colleague further south.
Not too far though - just 20 miles down the road at the University of Leicester (still in the East Midlands of England).
That's where Professor Eric Hope, a fluorine specialist, showed us all sorts of great stuff.
Eric originally had four demonstrations planned... First he used liquid nitrogen to cool fluorine, revealing a bright yellow fluid which looked like a urine sample!
Then he allowed very small pulses of fluorine gas react with steel wool (iron), charcoal briquettes (carbon) and cotton wool (mainly carbon).
However it was all so exciting that Professor Hope decided on the spot to dig out some Iodine and Sulfur - we did them too.
Here's a bonus video showing all the reactions from all the angles, including with our high-speed camera!
Didn't want anyone to miss a thing.
Finally, here's some extra interview footage with Professor Hope which didn't make the final cut but was still fascinating, so I posted it to our Test Tube site which shows you all sorts of extras from behind the scenes.