Here are some we've done...

Three chemists do their best to destroy pumpkins using all the tricks up their lab coat sleeves! More chemistry at http://www.periodicvideos.com/ Follow us on Facebook at http://www.facebook.com/periodicvideos And on Twitter at http://twitter.com/periodicvideos Periodic Videos films are by video journalist Brady Haran

The mysterious Neil drops red-hot charcoal into a cauldron of liquid oxygen.

More mind-mending particle physics from the guys at the University of Nottingham. Happy Halloween? Visit our website at http://www.sixtysymbols.com/ We're on Facebook at http://www.facebook.com/sixtysymbols And Twitter at http://twitter.com/#!/periodicvideos

To mark Halloween we're discussing vampire numbers. More cool sciencey Halloween videos at http://www.youtube.com/playlist?list=PL9eEsN9D48mf8CIYU1wRnWak0lcAnJN1u This video features Dr James Grime and Professor Ed Copeland.

The periodicvideos team demonstrates a laser dye for Halloween. More chemistry at http://www.periodicvideos.com/ Follow us on Facebook at http://www.facebook.com/periodicvideos And on Twitter at http://twitter.com/periodicvideos Periodic Videos films are by video journalist Brady Haran

Image credits below... For Halloween we look at a couple of "witch" objects in space.

666 (and sometimes 616) is the notorious Number of the Beast... what's all that about? And what has roulette got to do with it!? Pete Watts shares all sorts of other interesting bits of trivia from the Bible at Brady's Bibledex channel: http://www.youtube.com/bibledex

We discuss blood - both real and fake - for our 2010 Halloween special. Includes an explanation about hemoglobin, aka haemoglobin. More chemistry videos at http://www.periodicvideos.com/

Did you realise modern candle wicks are a marvel of engineering? The Professor takes a look at candle chemistry in this special video for Halloween. More chemistry at http://www.periodicvideos.com/ Follow us on Facebook at http://www.facebook.com/periodicvideos And on Twitter at http://twitter.com/periodicvideos Periodic Videos films are by video journalist Brady Haran