Monday, March 16, 2009

Water-The Unplugged Project of the Week

"Water, water everywhere, nor any drop to drink." Rime of the Ancient Mariner
This line kept going through my head all the past week as I was thinking about the Unplugged theme of the week-WATER. I wasn't up to diving into this epic poem, so I settled on some fun water experiments.

Our first experiment is a magic toothpick trick, which showed us how dish detergent breaks the surface tension of water.
We needed:
six toothpicks
dish detergent
a pie plate of water
At first we arranged 5 toothpicks into a pentagon in the pie plate of water.
It took some patience to form this pentagon, but we did it.
We then dipped the 6th toothpick into dish detergent.
When we poked this toothpick into the water at the center of our pentagon,
the pentagon toothpicks immediately floated away from each other. We learned that the soap broke the surface tension of the water, making the molecules of water break apart from each other. We see this when the toothpicks spread out.
Another fun surface tension experiment is seeing how many drops of water you can get on the top of a penny with a dropper.
First, we took guesses as to how many drops the pennies would hold. The kids guessed one or two.
It was very exciting and impressive when we managed to put 24 drops of water on the top of a penny. We carefully checked out our dropper and 20 drops is about 1 ml. We could see the surface tension of the water holding actually over the edge of the pennies.
We learned that water molecules are so attracted to each other the want to stay "stuck" together. If we poked the water with the tip of a toothpick, the tension was broken and the water flowed off the penny.
VERY COOL!
Becky set the record with 29 drops of water on a penny.
We then set out to find out why they put salt on our roads in the winter.
Using a:
bowl of water
string
table salt
ice cubes,
we discovered how to lift an ice cube with a string.
We put the ice into the water, laid the string on top of the ice, and then shook salt onto the string and ice.
After waiting about a minute, TA DA, the string picked up the ice.
The salt lowers the freezing point of water. The ice melts around the string and then refreezes with the string frozen to the ice.
Gracie did it,
and so did Luke.
Make sure you go and check out all of this weeks Unplugged: Water activities.

6 comments:

Infant Bibliophile said...

Those are some great ideas; thanks for sharing them.

Jennifer said...

Those are very interesting experiments.

Mom and Kiddo said...

All three of these science projects are ones I have been thinking about doing. Now maybe I'll be motivated. :)

heavenly bliss said...

Great job. I love experiments. We are really focusing on science for a while and actually did a few experiments today. We used a pan of milk and dishsoap. Can you guess? You'll have to check it out tomorrow!
xoxo Jenny
Great photos at the playground and at the lake. We tend to forget what the sun feels like huh?

Rhonda said...

I like the water tension experiment with the penny. 29 drops of water on a penny! Very cool!

Alicia said...

What a lot of great experiments! We've done some of them but never all in one marathon and some were new to me. Neat stuff. :)