Walking Water Rainbow Experiment

I had so much fun with this experiment the other day!  You really need to try it – it just blew me away! I saw it on Pinterest and I was intrigued and wanted to do this with my kids – C is 7, S is 5.  I stopped by the dollar store and got paper towels and plastic cups and I was ready to go (I already had food coloring and liquid water colors).  I tried it out while they were both in school so to make sure it would work – things don’t always seem to turn out as expected when doing Pinterest projects.

It is such an easy experiment to set up – set up 7 plastic cups in a row (or you can do 6 in a circle – but I found it harder for the kids to make observations when they were in a circle). Fill the first cup with red water, followed by an empty cup, yellow water, empty cup, blue water, empty cup, and finally a red water cup.  Fold paper towels lengthwise into fourths so they are long skinny strips.  Fold the skinny strips in half to make a V shape. Then connect the cups with paper towels placing the end of the paper towel strips into adjacent cups (red cup to empty cup; empty cup to yellow cup, etc). There are instant changes – the colored water starts traveling up the paper towel pretty quickly.

I was amazed – my kids were amazed. My son (5) immediately made the prediction the colored water was going to go into the empty cups and mix.  It was a great activity for little ones to introduce science practices – observations and predictions, and introduce or review color mixing.  As I did the experiment, I realized that there was complicated science going on behind the scenes and realized this would be a great experiment for older kids to learn about the water molecule and its properties: adhesion, cohesion, and capillary action.  So I made it into a lab I could use in my classroom and adapted it to be used at lower elementary, upper elementary, and middle school.   We let the experiment sit on our counter for 3 days to see the changes.

I set up the experiment with food coloring and liquid water colors to see what worked the best.  Both worked well, but I had new liquid water colors so I ended up using those with my kids.  You don’t need a lot of color, the color on the paper towels becomes darker over time. I way overdid the color in the pic above (bottom right). The colors were too dark to see the colors mix in the cups.

Once we were done experimenting, we used the liquid water colors to make a resist painting.  The kids drew on their paper with white crayon and then painted over it.  The area with crayon did not absorb the color.  It tied in with the experiment and was a fun way to use the leftovers.  We sprinkled some salt on the paintings too since that it always fun to see the changes with sale.

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Rates of Weathering Lab

Don’t you just love it when your lesson goes well!  Whenever I do a lab with my sixth graders, I set is up as best I can – plan everything down to the smallest detail, but there is an element of randomness that cannot be controlled.  So once I get them started,  I always cross my fingers and hope for the best.  Many times I am scribbling down notes for small tweaks to improve it for the next time, but not today!!  Today went off without a hitch.  My students were motivated, they were focused, they got their experimenting done in a timely manner, and they drew accurate conclusions.  (Just a sidenote  – I remember early on in my teaching I asked my students to “draw conclusions” and the look of confusion on their faces – one brave child asked me, “How are we supposed to draw that?!?”)

Today’s lab modeled chemical weathering in the classroom – find it here!  We looked at how climate affects the rate of weathering.  We used alka-seltzer tablets to represent rock and the students worked in lab groups to create their own procedure to test our testable question:

“How does the temperature of water affect how fast an alka-seltzer tablet dissolves?”

The students had to create a procedure that included 4 different tests to test a different temperature.  They were given the following materials:  Hot water, room temperature water, and ice)  Here is one group’s procedure:

Some groups needed a little guidance creating a 4th test.  They all could figure out testing in hot water, room temperature water, and ice water, but then some got stuck.  I reminded them that temperature is like a number line so they could mix different amounts of the supplies to get different temperatures.  This was enough to get most groups going.  A few groups needed an even stronger hint so I would ask them if they thought they could make warm water.  Once all groups had their procedures made they were all very self directed since they created their procedures they knew exactly what to do.  It was beautiful.  I gave them 20 minutes to test to keep them focused.

 

We had new digital thermometers that the kids loved.   They measure to the nearest 1/10th of a degree and you can choose Celsius or Fahrenheit.  We got them for a future lab where we need precise measurement but since they came early we got to try them out.

After testing, the students worked on their conclusions.  The conclusion related our lab results to the effect of climate on the rate of weathering.  They read a short passage and then wrote a C-E-R conclusion.  Some students needed a little help getting started so I provided sentence starters on the ELMO.

It was a fun day of teaching.

Mining for Chocolate Chips

I got back to school this week after spending a week in a half in Costa Rica.  It was so amazing and will need its own  post soon! Since I missed a couple days of school due to the trip, I felt like my students needed a fun engaging activity when I returned so we did one of my favorites – cookie mining!!  The students have been learning about the rock cycle, natural resources, and mining so I wanted to do a hands on activity to illustrate the effects of mining on the environment.   

It is a super easy activity and requires little prep so it was perfect to do on my first day back.  You need copies of the handout – mining area and questions, chocolate chips (I use Chips Ahoy) and toothpicks.  The students put their cookie on their mining area and try to extract as many chocolate chips as they can in 2 minutes and then examine the effect on their land.  It was interesting to see that the students had 2 main mining strategies – some students destroyed their cookies (and land) to get every chocolate chip out.  Other students were motivated to keep their cookie whole so they could eat a whole cookie at the end of the activity so they had much less mess. This led to a good discussion at the end about different companies and why they might use different mining practices.  All in all it was a great day!  My students loved it and made me feel like super teacher for giving them cookies on my first day back.