Materials:
1. 2 cups of cornflour or cornstarch
2. A cup of water
3. Food dye (Green is normally the preferred color)
4. Big mixing bowl
5. Apron (The activity is a bit messy)
Instruction:
1. Add the cornflour, water and two drops of food dye into a big mixing bowl
2. Mix the cornflour, water and dye with your hands for a few minutes.
3. Once done, try rolling the mixture into a ball with your hands. Then see what happens when you stop rolling it.
4. Pull it out and let it dribble through your fingers.
Explanation:
Cornflour is made up of lots of long, stringy particles that don't dissolve in water. However, they do spread themselves out, which allows the goo to act as both a solid and a liquid. When you roll the mixture in your hands or apply any force to it, the particles join together and the goo becomes solid. But if you let the goo settle or hold it up to allow gravity to come into play, it dribbles about as the particles slide over each other in liquid form.
