Number 21: Halloween slime

Halloween is almost here and so it is time for some messy mayhem! Time to roll out the classics, cornflour slime! All in funky comic book format.

I love playing with this stuff, its sooo simple and so much fun. OK it makes a bit of a mess, but it's only flour. Plus it doesn't splash, try making a big bowl of the stuff and then hitting it.

What to know more?

The cornflour water mix creates something called a non-Newtonian liquid. Basically, when you shock the liquid it turns to a solid. Ketchup is another example, that's why hitting the bottom of the bottle to get it out doesn't help much. It turns out this is really useful effect (not the ketchup), some bullet proof vests use the same principle and someone has even suggesting filling pot holes with this cornflour mix. 

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.