Friday, September 18, 2009

school holiday fun - make an oobleck!

With school holidays coming up, here's an idea for a messy, gooey, simple, educational, fun holiday project, which is easy to make and easy to clean up afterwards: make an oobleck!

An oobleck, as we all know, a kind of colloid, in which solid particles are suspended in a liquid. It's a mysterious substance which is sometimes solid and sometimes liquid - and lots of fun to play with!

If you put pressure on it, it becomes a solid, and you can roll it into a ball between your hands:

If you take the pressure off, it becomes more liquid:

until it flows through your fingers:

So how do you make it? Simple! Put 2 cups of cornflour into a bowl and add a few drops of food colouring. Add 1 cup of water - SLOWLY! - while someone else mushes the mixture in the bowl by hand. Then have fun!

While you're at it, why not read Dr Seuss' Bartholomew and the Oobleck? Science, story-reading, and slimy fun, all in one!

1 comment:

Lucy said...

Oooh we love this too... great idea! The best bit is you can sweep up the mess when it's dry :)