Earned Activity: Elephant’s Toothpaste

Whew!  I has been a while since I have posted.  We had an amazing spring break and Easter and I am trying to get back into the swing of things at work.  As the year begins to wind down I find I need to extra fun activities to keep the kids (and me) engaged in class.

I have students earn “minutes” each day towards an earned activity.  It is an extra activity that ties in with the current curriculum (or sometimes just for fun).  It is always a FUN activity that the student’s look forward to and motivates them to behave in class.

Once students have earned enough minutes, we set aside time in the day to do the activity.  This week we did Elephant’s toothpaste.  I picked up the ingredients: Yeast, 6% hydrogen peroxide, soap, and empty water bottles.  I got the hydrogen peroxide at Sally’s beauty supply and I am a sucker for a deal so I bought a gallon (it was only $2 more than the half gallon)

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There is something so magical about this reaction – steaming coils of foam erupting from the water bottle!  It never gets old!

I have it written up for different grade levels in my TPT store. Check them out:  K-2 focuses on the scientific method, 3-5 focuses on physical and chemical changes, and 6-8 focuses on chemical reactions.


Teaching Heat Transfer – Middle School NGSS

I have been having so much fun teaching heat transfer to my 6th graders!  I am really mixing it up this year since we are transitioning to NGSS standards.  There are so many fun and easy hands on activities to help the kids understand the concepts.  I have been finding that deep level understanding is a challenge for many of my students and this is leading to misconceptions.

I introduced heat transfer with an activity about thermal insulators and conductors (but I didn’t use introduce those words) where students feel and record observations of 3 different materials – wood, styrofoam, and metal (these materials had all been sitting at a constant room temperature).  The metal felt colder than the other two materials, but then, when the measured their temperatures, they were all the same temperature.  This led to some confusion – a great discrepant event.  Many students were stymied and even came to me saying their thermometers didn’t work.  I love baffling my students.  In the final part of the activity, the students put ice on the 3 materials and predicted which would melt the most and then tested the prediction.  It was interesting how many students chose styrofoam because it “felt warmer” even though it was the same temperature as the others.  The rest of the class thought they would all melt the same amount since they were all the same temperature – once again, they were amazed to see that the one on the metal melted the most.  This activity was a great use of discrepant events and phenomena that we could refer to for the rest of our study of heat transfer.


The second day we did some notes on heat transfer – using a demonstration to get students thinking about what is going on with the movement of particles and drew heat transfer diagrams showing the direction of thermal energy transfer.  We also reviewed radiation, conduction, and convection.

On the third day I wanted to check their understanding of the concepts so I used this Page Keeley Probe – The mitten problem.  I made a graph of the students results and then we had a great debate in class about which idea was correct.  During this students did a great job using the idea of heat conductor and insulator, but it was clear there were still some misconceptions. Many students thought the mitten thermometer would be warmer since “mittens keep your hands warm” and failed to realize there was no heat source.  Other students had the idea that the “cold would get out of the mitten” even though we had spent time focusing on cold being lower energy, they still thought cold was something that can move.

We did another activity with metal washers to see how the number of hot washers put in cold water affected the temperature of the water.  It was really easy to see that more washers had more thermal energy to transfer to the water.


Finally, the students completed a STEM challenge to design and build an insulated container to keep an ice cube cold.  They got to choose fro ma variety of materials to build their container and then they calculated the %remaining.  It was really interesting to see what materials the groups chose.  A could groups chose to line their container with aluminum foil and they ended up having less remaining than the control (an ice cube without insulation).  When I asked them after why they thought they got these results they realized that foil was a thermal conductor and was not the best choice for their project.


Water Bottle STEM

Have you noticed that middle school students get obsessed with the weirdest things?? This year at my school it is the water bottle flipping phenomenon.  Trying to flip a water bottle and get it to land without falling over.  They do it CONSTANTLY.  They never seem to choose quiet activities to obsess over.  The sound of those water bottles crinkling and landing is one of the most annoying sounds ever.


We have one more week of school until the winter break – for me it is actually just 3 more days.  I just finished a unit and I didn’t want to start something new right before the break so I decided to use the time to reinforce some of the science practices.  I haven’t had the students  design their own investigation yet and thought this would be a good time.  So I decided to create a lab based on the water bottle flip.  My students were going to determine the volume of water to add to the water bottle so it has the highest flipping success rate.  The students worked to design and test their experiment.  They were given some guidelines and then they were free to test.  It was a lot of fun.  The kids loved it!!   After performing the tests, the students used math to analyze their data – converting from fractions to decimals and then to percents, graphing their data, and sharing their data. Later in the week they are going to plan an independent investigation looking at additional variables that might affect water bottle flipping like the size of the bottle, the type of water bottle, the brand of the water bottle, etc.

It was super easy to get all the materials.  I went through the recycle bins around campus and got lots of water bottles and I had rulers and beakers.  The bottles got pretty beat up after each class.  They seemed thinner than I remembered, but that is probably good since they are using less plastic, but the denting around the bottom may have affected our results. I definitely needed new bottles for each class.   I want to look into using gatorade bottles since they are much sturdier, but I am not sure how they flip.  I spent about a half an hour with my own kids sitting on the floor flipping water bottles to practice before the lab.  If you haven’t ever tried it, it is pretty addictive and it feels awesome when one lands.