Making Oobleck, the strange goop with amazing properties
Ever had a hot, steaming cup of Oobleck? Geez, I hope not. The stuff is nasty! But it does exhibit some interesting properties…
- Put one and one half (1 1/2) cup of cornstarch into the bowl.
- Add one cup of water.
- Mix well.
Slowly dip your finger into the gooey mixture. Feels liquidy? Grab some in your hand and pour it back into the bowl. Now, try slapping it hard with your hand or a heavy spoon. What happens?
The molecules in Oobleck (sometimes spelled Ooblech) are very large compared to, for instance, molecules of water. When slapped quickly, they tangle themselves up preventing any splattering. In this way the mixture behaves more like a solid. When you slowly poke your finger into the mixture it easily slides right through. In this way the mixture behaves more like a liquid.
Oobleck experiment notes
A molecule is one of the basic units of matter. It is the smallest particle into which a substance can be divided and still have the chemical identity of the original substance. If the substance were divided further, only molecular fragments or atoms of chemical elements would remain. For example, a drop of water contains billions of water molecules. If one of those water molecules were separated from the rest, it would still behave as water. But if that water molecule were divided, only atoms of the elements hydrogen and oxygen would remain.
Oobleck is an example of a non-Newtonian fluid – a fluid that does not follow Newton’s law of viscosity.
The name “oobleck” is derived from the Dr. Seuss book Bartholomew and the Oobleck.
A person may walk on a large tank of oobleck without sinking due to its thickening properties – as long as the individual moves quickly enough to provide enough force with each step to cause the thickening. If they slowed down, they’d sink.
If oobleck is placed on a large subwoofer speaker and played at a high volume, it will thicken and form standing waves in response to low frequency sound waves from the speaker.
Ketchup is an example of a non-Newtonian fluid. It becomes runnier when shaken.
Oobleck slime experiment supplies
Supplies: Corn starch