Activity Day–Bartholomew and the Oobleck

If you’d like a recipe for fun, and a mess, find a group of 5-year olds (or any age for that matter) and add a healthy portion of oobleck.  Stir well and stand back!

Prior to mixing up our oobleck,  we read “Bartholomew and the Oobleck”, then we discussed solids and liquids and the properties of each by using a rock and some water (green in honor of St. Patrick).
Then we gathered round as I started to mix up our concoction.  Then each child attempted to stir.

I pointed out the different textures that appear in oobleck.  Then I demonstrated how the oobleck is hard and solid when you try to pick it up, but then it turns liquid and runs back through your fingers.

Then we divided the oobleck and let them have at it.  I was surprised to find that none of the boys wanted to get their hands in it.  But one of the girls was in up to her elbows!

Oobleck Recipe2 cups of corn starch
3 drops of green food coloring
enough water to make a thick mixture (about the texture of pancake batter)

I usually measure equal amounts of water and corn starch, but mix water in slowly.

Mix all ingredients together. This makes a fun mixture to play with textures. Use different utensils, such as a spatula, bowl, and funnels, to see what form the mixture will take.

Some other fun things to observe about OOBLECK:

• Oobleck is a solid and a liquid at the same time.
• If you make a ball and throw it up in the air, it loses shape and becomes flat in the air.
• Oobleck can be molded in a container and when taken out does not keep shape.
• If you fill a balloon with 0obleck, the air presses or forces the Oobleck back out.
• When you leave Oobleck in the sun, the color evaporates, it turns hard like cement on the top and like jelly on the bottom. When heated this also happens and it is sticky.
• Oobleck does not bounce.