Number 20: Black Worms

Firework season (in the UK) is approaching so I thought it would be fun to find a simple homemade pyrotechnic. And here it is, 'black worms' made with stuff you're bound to have around the house.

You'll need:

• Icing or powdered sugar (if you haven't got any already then just wizz some granulated sugar in a food processor).
• Bicarbonate of soda
• A pot of sand
• An alcohol based handwash gel
• A pot and a teaspoon
• Matches or a lighter

Safety: 

We're using flames and flammable materials so this is best done outside and with adult supervision.

What to do:

1. Mix 2 teaspoons of icing sugar with 1/2 teaspoon of bicarbonate of soda.

2. Make a small depression in the sand and then spoon the sugar/bicarb mix into it.

3. Squirt the handwash gel all the way around the pile of the sugary mix.

4. Light the gel and watch the snakes grow!

What's going on?

The handwash gel contains ethanol which burns pretty well. This heats up the bicarbonate of soda, which gets converted to carbon dioxide, sodium carbonate and water. Meanwhile some of the sugar starts to burn i.e. it reacts with the oxygen in the air, and ends up as more carbon dioxide and water plus  a whole load of stuff that comes form sugar that didn't burn completely. This is what causes the carmel smell and black sooty stuff.  Then all that carbon dioxide forms bubbles in the caramelised sugar and sodium carbonate which causes it to rise up as those little worm like towers.