Monday, February 3, 2014

The Water Cycle in action!

I love LOVE LOVE teaching science.  Last week we started our weather unit. Today's topic was the water cycle.  I started off reading from our science big book, useful, but no real memory burn there!  I had my students stand up and I taught them the water cycle song. (video to come tomorrow!)

After our wonderful rendition of the water cycle song, I called my students over to the table.  I poured some warm water into a cup and placed plastic wrap on top, securing it with a rubber band.  I asked my students what happens to accumulated water?  We came to the understanding that it evaporates.  Then, I asked my students, what happens when those water droplets (water vapor) meets cooler air?  Again, we came to the understanding, it condenses and forms clouds.  This is when I placed ice cubes on top of the plastic wrap.

Ice cubes on top of the plastic wrap.

I had my students go back to their seat and draw what they observed so far on their experiment sheet.

Click on the picture of the document to printout your FREE copy.
This document is great for explaining each step of the experiment to the teacher and to the parents when it comes home!

While we waited for 15 minutes, I had my students make a water cycle movable diagram. It showed the different stages of the water cycle with a raindrop that attached in the middle with a brad.  I would upload a free copy of this as well, but it is copy righted at I can't. (Insert Debbie Downer music here!)

After the 15 minutes was up, I called the students back to the table and I took off the ice cubes.  I asked a student to share with me what they noticed. She shared with us that there was water on the plastic wrap. I also asked, why did the water collect on the underside of the plastic wrap?  One of my sweet little ones, said that it was like the water collecting in the sky to make clouds!  WHAT?!  I was floored that she made the connection so quickly! 

I had my students go back to their places and draw in the second circle, what they predicted would happen next.  After prediction, we observed the container to see if our predictions were correct. I placed the container under the document camera so everyone could get a good look!

Apparently observing the container upside down is scientifically necessary.

Slowly, but surly we saw some drops fall from the plastic wrap and into the water.  My students were so excited to see this happen!  I had everyone return to their places to draw the outcome in the third circle.  We discussed that when water vapor that forms clouds is cooled, it condenses.  The droplets combine and adhere to other small particles in the atmosphere.  (Just like the droplets combined and adhered to the plastic wrap.)  When the droplets become heavy, they drop from the clouds in the form of precipitation.  Precipitation can be in the form of rain, hail, sleet or snow, depending on the temperature.

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