Sunday, July 25, 2010

Ice and Oil, Another Experiment on Density

We did our Sunday Science Experiment differently, thanks to some thoughts from Janet Parks Chahrour's Flash! Bang! Pop! Fizz! Exciting Science for Curious Minds, which encourages children to write down a hypothesis, make predictions, and record observations.

Before Sunday school this morning, I asked the children to think about what they already know about water, and oil. From experiments we've done in the past, they know water is denser than oil. When you pour the two together, water will fall to the bottom of the glass, and the oil will sit on top of it.

Then, I asked them what they know from past observations of water, and ice. And, they were able to tell me ice is less dense than water. An ice cube will float on the surface of water.

So, I asked them to think about what might happen if you put an ice cube in a cup of oil. Hmm...

After, Sunday school, we discussed it. Some of the children thought the ice would still sink right to the bottom of the oil, just like water. Some, thought it would float, just like in water. While others thought it would sit in the middle.

After we discussed it, I presented them with three glasses. One full of oil, one full of water, and one with a little oil. We reviewed what we knew already, by dumping some of the water into the oil, and watching it sink.

Then, I gave the children some colored ice cubes, I had prepared ahead, and let them put one into the water, and one into the oil. At first, the ice in the oil, floated near top, but not as high as the ice in the water. The ice in the water immediately started dropping color into the water, too.

One of the children pushed the ice cubes down. The one in the water, popped right back to the top. But, the one in the oil just sat in the middle of the glass.

Finally, we observed the ice cube in the oil, and watched as air bubbles escaped from the melting ice, and headed to the surface, while the melting, colored, water dropped straight to the bottom of the glass.

For more fun with science, check out this week's Science Sunday link-up at Adventures in Mommydom.

It's great to be a homeschooler.


Christy said...

Great idea to color the ice cubes. I had no idea what would happen to the ice cube in the oil. Fascinating.

Joyful Learner said...

This is fascinating! All through while reading this, I kept on's going to, no, it's going to stay in the middle, etc. Love the demonstration!

Debbie said...

I will have to try this so we can see it first hand, I know Selena woud get a kick out of it, maybe after vacation.

Ticia said...

That is so cool! I bet they loved this.

And yes the kids did observe what the stupid caterpillar had done to my poor tomato plants. Sigh, I think I'm not made to be a farmer.

Phyllis said...

Very cool experiment!

Raising a Happy Child said...

This is a really great "Wow" experiment - I think Anna is going to love it. Thanks for sharing it!