Why is oobleck a colloid

If you gently pour it, applying little force, it will flow like water. This kind of fluid is called a dilatant material or a shear thickening fluid.

It becomes more viscous when agitated or compressed. Another non-Newtonian liquid is ketchup. Ketchup behaves in the opposite way from Oobleck. Liquids like this are called shear thinning liquids. If you leave a bottle of Ketchup on a shelf, it becomes thicker or more viscous.

Nearly everyone has experienced this while trying to pour the liquid from a new bottle — it refuses to move. If you shake the bottle or stir it up, it becomes less viscous and pours easily. When sitting still, the granules of starch are surrounded by water. The surface tension of the water keeps it from completely flowing out of the spaces between the granules. The cushion of water provides quite a bit of lubrication and allows the granules to move freely.

But, if the movement is abrupt, the water is squeezed out from between the granules and the friction between them increases rather dramatically. The first thing you have to do is simply place your hands into the Oobleck and start squeezing it. Have some fun! Is an oobleck the same as as a polymer like goop? What is the physics behind oobleck? Liquid Liquid Nitrogen 1. Oobleck Liquid Nitrogen Image Answers. Source: sciencebuddies. How to make Oobleck www. Oobleck: Is It a Solid or a Liquid?

In this case, solid particles are mixed into a liquid. To separate this mixture the water can be evaporated away to leave the cornstarch - this will happen quickly if the oobleck falls as drops on a surface.

Water and other liquids have certain properties and behave like many familiar fluids - if you stir them they move out of the way quickly. Oobleck doesn't act like these - when oobleck is hit or moved suddenly, it gets more rigid, or viscous. Something that behaves in this way and changes it's viscosity thickness is called a non-Newtonian fluid.

Why does ooblek behave in this way? If moved slowly, the cornstarch particles have water between them which allows them to slide past each other. But if ooblek is moved quickly or hit, the water is squeezed out from between the particles and the friction between the cornstarch particles increases a lot, locking them together so they can't move past each other.

Quicksand is also a non-Newtonian fluid, but it acts in the opposite way from ooblek, when hit or pressure is exerted on it, it becomes more fluid. If you ever find yourself sinking in a pool of quicksand, try swimming toward the shore very slowly. The slower you move, the thicker the quicksand will be and so you can push against it. Ooblek with vegetable oil is electrostatic. Try this stuff: styrofoam rubbed in hair brought nearby.