Sunday, July 4, 2010

July 4th is a Chemistry Holiday

It's just not July 4th without fireworks, and fireworks are all about chemistry!

I'm attending a chemistry workshop in Connecticut and have science on the brain (anyone else out there spend their Independence Day deriving the Nernst equation??), so July 4th brings to mind the science behind fireworks.

  • Check out this NOVA website for a neat description of the anatomy of a firework.
  • Here's a C&E News article about environmentally friendly fireworks
  • While watching the show tonight, you can figure out which chemicals are in the fireworks, based on color. Here's a nifty chart correlating which compounds produce which colors:
Color Compound
Red strontium salts, lithium salts
lithium carbonate, Li2CO3 = red
strontium carbonate, SrCO3 = bright red
Orange calcium salts
calcium chloride, CaCl2
calcium sulfate, CaSO4·xH2O, where x = 0,2,3,5
Gold incandescence of iron (with carbon), charcoal, or lampblack
Yellow sodium compounds
sodium nitrate, NaNO3
cryolite, Na3AlF6
Electric White white-hot metal, such as magnesium or aluminum
barium oxide, BaO
Green barium compounds + chlorine producer
barium chloride, BaCl+ = bright green
Blue copper compounds + chlorine producer
copper acetoarsenite (Paris Green), Cu3As2O3Cu(C2H3O2)2 = blue
copper (I) chloride, CuCl = turquoise blue
Purple mixture of strontium (red) and copper (blue) compounds
Silver burning aluminum, titanium, or magnesium powder or flakes

Why does John Bonham sound so sweet on drums?

Apologies for the lack of recent updates - usual end of year business. Whilst catching up on email, I came across a link sent to me by an old school friend who went on to do a PhD in Pyschology. It is a fantastic podcast by Jarvis Cocker (English musician, frontman of the band Pulp) about how we perceive music and its evolutionary significance. He does this by transporting the listener to the recording session in which Led Zeppelin laid down the famous drum intro to the song "When the Levee Breaks" from their 4th album.
For me, it doesn't get any better than combining cognition, evolution and Led Zeppelin...... Click here to listen to Jarvis's dulcet Yorkshire tones describing how sound is created and subsequently processed in the ear and brain.