Dark wet fall weekends are perfect for family home life. We cozy up, bake, make, read, play, and spend time together. Science is big in our house - there is always something on the to-do list, and there is always a basket filled with something or other we want to play around with. Sometimes we do bigger projects - program a robot, make a solar oven, look through the microscope for specific somethings, test water or soil, see what happens. But sometimes the small projects are really fun too. And they are fun to repeat and even if simple they never quiet get boring (at least with my boys).
One of those endlessly fun things is the cornstarch project. You mix water and corn starch and get a funky substance that is both a solid and a liquid. The thing is water and corn starch don't completely mix. Their molecules slither around each other. The corn starch molecules get tangled up, but the water molecules flow around them. So, if you whack the substance hard, the molecules don't have time to move and it feels like a solid. When you move into it slowly however, the water molecules have time to flow around and it is a liquid. It is messy. It is fun. And it is easy to do.
You might want to cover your table with something.
Pour 2 cups of corn starch into a bowl. Measure 1 cup of water and add a few drops of food coloring if you want. Stir. Slowly add the water mixture into the corn starch, stirring as you go. Mix it up - it should be really thick and hard to stir. If you can't stir at all add a little more water, but it should be a bit of a struggle.
Now, go! First try to hit the mixture with your knuckles quickly.
Next, gently press your fingers or hand into it.
Goo is a long time of fun.
Another easy and fun one is making a lemon battery - with your tongue as the final connection. Batteries of course are made with two metals and an acid. One metal has a positive charge, one a negative and the lemon is the acid. By sticking your tongue on it, you complete the circuit and get the tingle.
Take a lemon and push while you roll it on the counter to get it juicy inside. Straighten a paper clip and stick it in the lemon. Take a piece of copper wire about the same length as the paper clip and insert it into the lemon near the paper clip. Touch it to your tongue! You should feel it tingle.
We had zinc and copper plates from another science kit, so used those and got a bigger tingle. Whoo hoo! :) We could also test the current by connecting it to a little LED light.
Very fun. Perfect family fun for a dark rainy day.
9 comments:
We used to do the cornflour experiment a lot, but really it was just a backdrop for my kid to play with her plastic animals and have them slowly sink into the muck. Tar pits all around. :)
I always remind everyone though: Don't pour the mixture down the drain!!
We love cornstarch and water around here. The lemon experiment sounds great, can't wait to try it. Thank you for sharing.
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I can't tell you how much cornstarch I have purchased for my boy over the years..... the gloppy mess is pure fun!!!
Every time we make it, I want to make a huge bowl full that we can run across!!! :)
Yesterday we had to purchase another gallon of vinegar for another favorite of ours. ;)
Very nice, thanks for sharing.
We love ooblek! We were just watching a Mythbusters episode where they made a huge vat and would run across the top and then stand in the middle to sink. That looked like so.much.fun. Love those non-newtonian fluids :o)
It's been a long time since we made that cornstarch thing. Thanks for the reminder! And the lemon thing is something I think my kids would like.
I'll definitely try that lemon battery with my boys! Thanks. Here's another fun thing to try with the cornstarch:
http://www.youtube.com/watch?v=Yp1wUodQgqQ&feature=related
We haven't done this yet, but I've always wanted to do it.
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