For today’s 15 minute focus (which we spent 25 minutes on), we learned about the States of Matter.

Prep for the Activity:

At least 12 hours before class: put an inch or so of water in a container. Freeze it for a couple hours. Sprinkle in some treasures: beads, marbles, plastic dinos, pennies…. really almost anything that can be wet. Then add another inch or two of water. Continue, making as many layers as you feel like. About 4 – 6 kids can work on one ice block. If you have more, I’d set up multiple batches.

Supplies:

For demo: ice cubes, one per kid. Towel. turkey baster, cup of water

The ice. A big tub to work in. Salt shakers with table salt. Small bowls of rock salt, with SMALL spoons. Spray bottles of hot water. Tweezers. Optional toothbrushes. Optional mallets. Towel.

Introductory Demo

I handed everyone an ice cube. I asked them what it was. They all said ice. I asked them what it was made out of. They said ice. I helped them notice how it was melting – I asked: “what’s that?” “Water.” “Yes, liquid water. So what’s the ice – it’s solid water.” We talked more about how if water got cold again it would turn back into ice, and so on.

I asked what happens when water gets hot, like on a stove. They didn’t immediately know, so I coached them through thinking about steam rising from a pot or a steamy shower, and how puddles evaporate on a hot day. We talked about water vapor / water as a gas.

I showed them a turkey baster. (You can also do this with a syringe or a ball pump or balloon pump.) Asked if it was empty or full. When they said empty, I said it was full of air, and I blew a little air at each of them. I showed them how if I put the baster full of air into a cup of water and blew the air out it makes bubbles that go through the water and escape into the air in the room.

Melting the Ice

Then I pulled out the ice activity. I showed them the “treasure” hidden in the ice. I explained that if we just waited long enough, the ice would melt on its own in our warm classroom. But, we could speed it up by sprinkling on salt (if you sprinkle salt on water, it will stay liquid at a lower temperature), or by spraying warm water on, using the toothbrushes to scrub the salt into the ice, and using tweezers to extract items. Do they think they can free all the treasure?

Then, they go to work. This will keep kids engaged for a long time!! They take turns with the different tools swapping the spray bottle for the salt shaker, etc.

You may or may not choose to offer the mallet option. As the ice starts to get more brittle, and porous, you can bang it with a mallet to speed things up, but you have to be careful not to bang anyone’s fingers!

Keep going till you’ve freed all the treasures or your time is up. Some people use a hair dryer too, but I haven’t.

Song / Book

We didn’t have time for either, but you’ll find recommendations for books, a song, and a movement game in my full post on States of Matter.