Kindergarten, Science, Week 11

Monday we learned that Water and Oil Push Apart.

• You'll Need: eyedropper, clear glass with water in it, rubbing alcohol, cooking oil
• Get a few drops of alcohol in the eyedropper. Put the tip of the eyedropper under the water and slowly squeeze out the alcohol. The alcohol disappears. 
• Now get a few drops of cooking oil in the eyedropper. Put the tip of the eyedropper under the water and slowly squeeze out the oil. Drops form and float to the surface.
• Why? Water and alcohol attract each other. The alcohol molecules grab ahold of the water molecules and form a solution. The water and oil push each other away. The oil molecules pull together against the pressure of the water and form bubbles. Water is heavier than oil, so the oil floats to the top.

Tuesday we learned what Water Can Do.

• You'll Need: Styrofoam disk (you can use a plate, I cut a large circle from a meat tray), scissors, pencil or large nail, water faucet
• Cut 6 1-inch slits (spaced evenly) around the disk and bend them to one side to make the waterwheel blades
• Push a pencil or nail (axle) through the center of the disk. Wiggle it a bit to make the hole just large enough for the disk to spin freely.
• Turn the faucet on so you have a fast stream of water.
• Hold the disk under the stream so that the water hits the blades.
• Experiment with the water hitting in different places and compare how the waterwheel spins.
• Why? The water pushes against the first blade and moves the waterwheel, then it hits the next blade, etc. until the waterwheel is spinning.
• You can talk about this powering mills in the "old days" and generating electricity today.

Wednesday we made a Deep-Bottle Diver.

• You'll Need: clear 2-liter plastic bottle with a cap, water, eyedropper that fits inside bottle
• Fill the bottle with water.
• Pull some water into the eyedropper.
• Now this is the tricky part because you need just enough water in the eyedropper so that if it still floats, but if it gets 1 more drop it will sink. At first I didn't have enough water in the dropper and it didn't sink. Then I had too much water and it didn't float at all. Once I figured it out, I filled a pitcher with water, pulled a bunch of water into the eyedropper, then expelled the water 1 drop at a time until it floated in the pitcher.
• Put the eyedropper into the bottle and screw the cap on.
• Press in the sides of the bottle, and release. When you press in, the eyedropper sinks, when you release, it floats.
• Why? Pressing in the sides of the bottle increases the water pressure inside the bottle and forces more water into the eyedropper, making it sink. Releasing the sides decreases the water pressure, lets the extra water out of the eyedropper, and it floats again.

Thursday we learned that Cold Sinks and Warm Rises.

• You'll Need: 2 small balloons, 2 clear jars, water, bowl, cold water
• Put some water in the balloons (they should be about the same size), tie the balloons, put them in the bowl and place them in the refrigerator for at least 30 minutes.
• After the balloons are cold, fill one jar with cold water (I used from the refrigerator, or you could make tap water cold by adding ice cubes). Fill the other jar with warm/hot water from the faucet.
• Place a balloon in each jar. In the cold water, the balloon floats. In the warm water the balloon sinks.
• Why? Because the water molecules in the cold water stick closer together, the cold water is denser or heavier, causing the cold balloon to sink in the warm water, since the water molecules in the warm water are father apart, causing the water to be less dense. In the cold water jar, the balloon floats because they are the same temperature.

After a few minutes, the warm water made the water in the balloon warm, so we switched the balloons to see it happen again.

Friday we cut and glued pictures of water on our "2". When I first told K. we were going to do this she ran and got her Bible Story book and showed me that God made the seas and rivers on the 3rd day. We got her Bible and we read the 2nd day again. God separated the firmament from the water, so there was water on the 2nd day.