Reflections of a Techie

Emerging conversation skills using Voicethreads

I'm so pumped because finally my students are getting technological enough that we're moving beyond learning the tool and how to best utilize it.  We're able to converse about a topic.

Take this week for example...some of them picked to use a Voicethread to present what they had learned about hydroelectric power.  Now I won't say these are ready for primetime yet, but they are huge steps forward on their part.  The content is there, the visual is there.  Now if I can just get them to tweak their writing mechanics and really learn to edit their work, we've got it all.

Take a look and see if you can see them holding a small conversation with each other.

More inquiry with probes...looking at water desalinization models

I was fortunate enough to receive a salinity probe....  Thankfully it arrived in enough time for me to use it this past week.  Students must learn how desalinization works and the struggle we always have is how to safely test the water.  You know you pound it into their heads not to taste ANYTHING...and now you're stuck not knowing how to "prove" that the salt was taken out.

Enter the salinity probe.

I set up the desal model using one flask on the hotplate....we measured it salinity before we started.  Then deciding that it could be our model of the ocean by adding one teaspoon of salt.  So we tested it again with the probe.  Sure enough the reading went from 0 to 47 ppt.  Now I don't have any mistaken ideas they know what ppt really means...but does that really matter? 

Nope they get that 0 means no salt and that 47 means more salt.
The biggest advantage of doing the lab this way is that it puts my kids in the role of analyzing data.  They can speak, using the evidence generated almost immediately, by the probes to prove their view of what happened.  I think it empowers them to be smart!!!!

We use clear tubing to connect our ocean to another flask that I submerged in an ice bath.  Thanks to the American Chemical Society's Inquiry in Action States of Matter activities...the kids immediately knew that we did that to enhance the condensation.  Hurray!!!!!  They get that temperature differences make an impact on what happens.

Anyway, we boiled the water and by near the end of class...almost 50 ml of salt water had evaporated from our ocean flask. The big moment came when I unstoppered the second flask and we put the probe in to measure the salt.

The reading went right back to 0.  I'm not exaggerating when I tell you that they jumped up out of their chairs and cheered.  I think that's because they felt like they got it and actually knew what was going to happen and why.  Our only unsolved mystery is why the remaining ocean water wasn't more concentrated than when we started.  The salinity measured at almost the same ppt.   So I have to do some research and experimenting to see what's up with that.

We're excited to continue using this probe as we explore what the impact of different levels of salt concentration is on the density of the salt water.  I'll keep you posted!!!!