World of Goo!

Since Caitie got to do her Spa Day, Gwen wanted to help me plan a class as well. We came up with The World of Goo. Once again, I tried to plan too many projects, but I guess that just leaves me with more for another class.

The toughest of the projects was the bouncy ball. I used a recipe adapted from an American Chemical Society activity, but wasn't very happy with it. After some experimentation, I had a better ball. (More on that tomorrow.) However, I guess I had made so many of the darn things by then that I took for granted the finesse involved. It's one thing to do the chemistry, quite another to actually mold the ball by hand. About half the balls worked out perfectly. A few kids over mixed and got crumbles. Some kneaded the mixture a bit too long and got odd shaped balls. I think if I do it again, I'll have extra set ups so that kids can repeat the experiment if needed.

From the science end we mostly talked about mixtures in all their glory. We discussed the differences between a solution (the most homogeneous mixture), suspensions (the most heterogeneous) and colloids (somewhere in between the two). We demonstrated colloids with one of my favorite non-Newtonian fluids -- Oobleck. The old cornstarch and water mixture has so many interesting properties and is just fun to play with. (And MESSY!) Then we made a Borax solution and tried our hand at polymerization. Yea, slime!

Anyway, below are the recipes we used and some others we didn't get to. Have fun!

World of GOO!!!

Slime

½ cup school glue – white or gel

1 tsp Borax powder

1 cup water

Food coloring

1. Pour the glue into a bowl. If desired, add food coloring.
2. In a separate bowl, mix water and Borax. Fully dissolve Borax into solution.
3. Slowly pour the glue mixture into the bowl of borax solution.
4. Place the slime that forms into your hands and knead until it feels dry. The more the slime is played with, the firmer and less sticky it will become.
5. Discard water in bowl.
6. Store your slime in a zip-lock bag in the fridge (otherwise it will develop mold).

Oobleck

1 ½ to 2 cups cornstarch

1 cup water

Food coloring

1. In a bowl, mix 1 cup water with 1.5 cups cornstarch.
2. Work in more cornstarch if you want a more 'solid' oobleck.
3. It will take about 10 minutes of mixing to get nice homogeneous oobleck.
4. Mix in a few drops of food coloring if you want colored oobleck.

Flubber

1 tsp Metamucil

1 cup water

Food coloring

1. Mix Metamucil with water in a microwaveable bowl. Add a drop or two of food coloring if you wish.
2. Place bowl in the microwave and cook on high for 4-5 minutes (actual time depends on microwave power) or until the goo is about to bubble out of the bowl. Turn off the microwave.

3. Let the mixture cool slightly, then repeat step 3 another four to five times.
4. Pour the flubber onto a plate or cookie sheet. (HOT!) Allow to cool.

No Cook Playdough

1 cup of flour

1 cup of boiling water

2 tablespoons of cream of tartar

1/2 cup of salt

1 tablespoon of oil

Food coloring

Simply mix all the ingredients together! Be careful as it can be quite hot.

Basic Salt Dough

1 cup of fine salt

1 cup of flour

1/2 cup of water (may add more)

1. In a large bowl, combine the salt and the flour.
2. Make a well in the salt/flour mixture and add the water.
3. Knead until smooth and shape into a ball.
4. When not in use, wrap in plastic or store in an airtight container.
5. This will air dry, but to speed it up, place in a 250 degree oven until dry (1 hour for flat shapes, more for 3D.)

Bouncy Ball

1 tsp Borax

2 tbsp water

1 tbsp glue

1 tbsp cornstarch

Food Coloring

1. Heat water until hot. Add borax and mix well. Add color if desired.
2. In a separate cup, put glue and cornstarch. Do not mix.
3. Add borax solution to second cup. Let sit for 10 to 15 seconds. Mix well.
4. When you cannot mix anymore, remove from cup and knead well with hands. Form into a ball.