Ooey Gooey Ooblek

This term in Year 3, students have been learning about solids, liquids and gases and how adding and removing heat can change their state. They have been doing a range of hands-on experiments and investigations, including with ice cubes, water, and eggs.

This week, they explored the unusual substance of ooblek. Oobleck is made from corn flour and water and is a non-Newtonian fluid, meaning it has properties of both liquids and solids.

Students mixed their own ooblek and used their hands to explore how it moves and changes when they added or removed pressure, when they squashed it, rolled it and when they let it drip from their fingers. They observed how when you slowly dip your hand into it, it acts like a liquid, but if you squeeze the oobleck or punch it, it feels solid.

We then discussed the science behind this fun phenomenon – when you add pressure (which is a form of heat), the size, shape, and makeup of the cornstarch grains causes the corn flour to “lock-up” and hold its shape (like a solid) when pressure is applied to it. However, as soon as the pressure is removed, it returns to acting like a liquid.

Want to try making ooblek at home? All you need is corn flour and water. Start with 1 ½ cups of corn flour and1 cup of. Experiment adding more of both as you mix it with your hands. Happy oobleking!