Week 11

Week in Review

Monday

We conducted an inquiry lab over conservation of mass today entitled Bag of Bubbles.  Students first massed a small amount of baking soda and a small beaker of vinegar inside a ziploc bag without mixing. 

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Then students mixed the vinegar and baking soda without opening the bag and remassed everything.

Students then compare the initial mass of ingredients with the final mass of the bubbles-filled bag and analyzed the difference.  Most groups had bubbles-filled bag weighing an average of 0.5 grams less than it did before the ingredients were mixed.

The question they had to answer - "Did the bubbles come out of nowhere OR were the bubbles already hidden inside of the materials, waiting to be released?"

They had to use their mass data as evidence in their conclusion and we discussed our results on Tuesday.

Tuesday

Once again I forced my students to think today, and ohhhhhhhh how they groaned!

As a class we discussed our results from yesterday's lab and here were the common responses...

• "Bubbles came out of nowhere because they weren't there before." 
• To which I replied, "So you think you are a magician?"
• "Bubbles came out of the ingredients because if they appeared out of nothing they would have brought mass with them because air is made of atoms and the final mass wasn't heavier."
• To which I replied, "Excellent, evidence-based answer. However, your mass got lighter rather than stay the same, are you a magician too? Did you destroy something in your experiment?"
•  To which they replied. "The final mass was lighter because we made bubbles. Bubbles are lighter than liquids and solids so the overall mass was lighter."
• To which I replied. "You crazy people! Are you telling me carbon and oxygen are losing protons and neutrons left and right every time it changes state from solid to liquid to gas. Sounds like the world is coming apart! Have you forgotten everything you learned about atoms from Unit 2?"

**  I realize this is quickly become quite nerdy for all of you non-science readers. However, I wanted to give you a taste of the back-and-forth conversation we were having because I think you could picture the looks of frustration and consternation on students' faces as I kept poking holes in their ideas and challenged them to revise their answers based upon prior knowledge. **

Eventually we came to the realization that (a) the bubbles were "hidden inside the starting the materials" (or rather the atoms were rearranged to make the bubbles and (b) we lost mass because the ziploc baggies had poor seals and some of the pressurized air escaped out the seams.

What was the point of sharing this long conversation?

D2L can NOT replicate this experience. I think teachers/administrators need to be careful in thinking online learning platforms can seamlessly replicate the type of back-and-forth, didactic instruction that occurs in the classroom.  I detest discussion boards in Blackboard, D2L, Moodle, etc... because (in my experience) they provide a farce of the rich discussion that occurs in a face-to-face environment.  If you would have been in my class on Tuesday you would have felt the emotion, the tension, and the communal effort as a group of 14 year-olds strained together to reach resolution. It was awesome, it was beautiful, and it cannot be replicated online.

Wednesday

Students complete a Practice Quiz to review and make sure they've understood the main ideas before taking a quiz over the last 2 weeks activities and learning goal.  They completed the practice quiz, then showed it to me and checked their answers with a key.  If they didn't finish in class they could check the key on D2L at home.  

Thursday

Students took Quiz 4.2 on D2L then began brainstorming in project groups for their 2 week long Rube Goldberg Project beginning next week. I'll be writing extensively about that project next post so I'll leave it be for now.

Friday

Aces Field Trip.