My husband had a great idea to do with the kids- perfect for sensory experiences and hands-on coordination! Not to mention just plain fun! Although I call it oobleck, The Teacher calls it GAK! This is a fun experiment which helps younger children to understand the difference between solids and liquids.
Food Coloring (optional)
bowl and cup
Have your child scoop some cornstarch into a bowl. Set aside. Then have a cup of water with any choice of food coloring desired. Let the child add some food coloring to the water- encourage them to find out what happens if they mix colors too!
Then pour equal parts of water into the cornstarch bowl. Mix thoroughly making sure there are no lumps.
The consistency should be smooth and slightly runny but not watery. There should be no lumps or thickness to it. You may need to add a little more cornstarch or colored water to get the desired result.
Now the fun thing with this gak is that it is a non-Newtonian fluid. If you slowly put your finger (or use a spoon) down through the substance it will stick to your finger and make a mess, just as if you would dip your fingers in a glass of water (fluid). But if you poke rapidly at the substance it will become hard (solid) as a rock, and you will not get messy at all!
I used to love “wowing” school kids with this experiment- although it can get messy quickly! You can pour your GAK in a plate, bowl, on the table, or even keep it in a cup. But you need to throw it away when you’re done as it will not maintain it’s properties- and don’t throw it down the sink!! It can separate can clog your drains!
Ideas of topics to discuss with your science fun depending on the age of the child:
the color wheel