Let's start out with Mrs. Karen's surprise! I found my son's old catching gear and brought it to school. It was still a little stinky, but no one seemed to care!
One of our fun projects this week was a cool looking car. Check it out and please notice that we used all of the shapes and colors that we studied, red circles, blue squares and yellow triangles!
Our special snack this week was a wonderful car cookie! I guess we could have just bought some cookie dough and cut a car shape but that's just not us. We made our from graham crackers, round vanilla wafers and yellow icing. They were a big hit!
Our two science experiments this week were a lot of fun. The first was ISO/THIXOTROPY. huh? Corn starch and water! :)
Here are my instructions -
Procedure: Place about a cup of cornstarch (aka corn flour) in a large bowl and add about a ¼ cup of water to the cornstarch. Keep adding water until the mixture appears somewhat thicker than pancake batter. With your hands, take a handful and knead the mixture, like you would bread dough. As the mixture is agitated or squeezed, it will become firm as long as continuous kneading or pressure is exerted. As soon as the pressure stops, the ‘batter’ will revert to its original form and ‘pour’ through your fingers. Even though the cornstarch and water is a liquid, you can form the stuff into a ball if you can squeeze and knead it quickly enough. The sensation of this in the hands is unique and must be experienced to be believed. It feels great!
What’s going on? This experiment demonstrates iso- and thixo-tropy properties of certain emulsions (fluid mixtures).
Isotropy is the property of a fluid to become firm when agitated. This is what you’re experiencing with the cornstarch and water. You can also see this while walking on wet sand at a beach. The sand firms up below your feet as you first touch the sand and then becomes more fluid, as your feet sink into the sand, just a moment later. If you run over the sand, the sand will feel very firm. If you walk slowly, your feet will sink below the surface with every step.
Thixotropy is the opposite of isotropy in that the fluid mixture becomes more fluid (less firm) as it is agitated. An example of this is where you strike the end of a ketchup bottle to get ketchup to come out of the bottle. The striking force temporarily causes the ketchup become ‘runny’ and it flows more easily from the bottle (and on to your new clothes - white ones). Another example is the infamous “quicksand”. If you thrash around in the quicksand, you will sink “quicker” because all that wiggling causes the sand to liquefy.
Mess Factor - Cornstarch is an edible, non-staining, harmless substance (probably one of the cheapest food stuffs you can buy), but this experiment tends to get cornstarch on clothing and the floor. The other thing about this experiment is that once you’ve put your hands into the cornstarch & water mixture (aka ‘glop’), you won’t want to take your hands out. It is quite a unique experience!
Things to Remember - Isotropic = cornstarch & water or beach sand Thixotropic = ketchup or “quicksand” [think of ‘thick ketchup’ for Thixo]
Think this is too hard for a group of three year olds? Think again, they loved it and tried to say every word!
The next experiment was just as simple but it had a WOW factor that even shocked me! I call it the Colorful Mixtures Science Experiment
What You Need:
Milk
Food coloring
Liquid dish soap
Dish- wide rim
What To Do:
1) Pour milk into a wide rimmed dish, and let sit until it warms to room temperature (THIS IS A VERY IMPORTANT STEP, the milk must be room temperature!)
2) Place drops of different food coloring in the milk
3) Place two drops of liquid dish soap into the mixture
Now stand back and watch!
Sorry there are no pictures, it is hard to coordinate photos with mess! :)
It was a great week! Next week we will be reviewing our shapes, colors and numbers while we study the letter "D" and talk about autumn! I can't wait!
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