View source for Oobleck

{| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right"
| [[Chemistry]], [[Physics]]:
| Non-Newtonian Fluids
|-
| Grade Range:
| [[Elementary School]]
|-
| Format:
| [[Hands-on]]
|}

This is a classic demonstration with corn starch and water, and it is a favorite among elementary students! This demonstration is messy, so be sure to have access to a sink and paper towels at the location.

== Materials ==

* Corn Starch
* Water
* Measuring Cup or Similar
* Two Large Bowls or Tubs
* Optional: Back Massager

== Safety Precautions ==

Please read the General Safety Precautions section of the [[Demonstration Safety]] page before performing this demonstration.

== Demonstration ==

# Make the Oobleck: Mix one part water with two parts corn starch in one of the tubs. Add more of either as needed to get to a consistency where it crumbles when you grab it, melts and drips off your hand when you hold it, and it is rigid if you hit the surface. You will have to mix it by hand!
# Fill the second tub with water, and let students come up and play with the Oobleck. Add more water to the Oobleck as needed, since it will dry out over time, and have students rinse their hands in the water tub after playing with it.
# To dispose of the Oobleck, first dilute it fully so it is no longer able to clump. After being diluted, it can be safely poured down a drain. If you don't dilute it, it will clog the drain!

== Why This Works ==

Oobleck is a ''Non-Newtonian Fluid'', which means it is a mixture that doesn't behave like other fluids. When we apply force to the Oobleck, instead of squeezing by or moving around the object, it stiffens up and resists it. This is because the corn starch molecules are pretty big, and they have a hard time sliding by each other. So, instead of trying to squeeze around each other, they stack on each other and make the fluid turn stiff. This is why the Oobleck can crumble, shatter, and be ripped apart! When there isn't a lot of force on it, it behaves like a normal fluid, which is why the Oobleck can drip, puddle and ooze!

== Additional Information ==

* This demonstration and [[Outrageous Ooze]] are favorites among elementary students!
* Ketchup and tomato sauces are also non-newtonian fluids, which is why ketchup can get stuck in the bottle and then spill out all at once!