The Acid Test
Testing Carbon Cycle Comprehension (or not)
So how could atoms of carbon from Einstein be in you?
Little pause here for you to think about it for yourself. It’s kind of a cool idea, of how we are all connected. I was hoping that some of the chemical equations, the review of respiration, their knowlege of respiration and the carbon cycle might have given them this insight. A few did make the connection. Mostly not though. It’s such a tease, moving between the big picture and the detail needed for tests (and for the basis of understanding).
I was surprised to see the persistent mis-conceptions of carbon returning to the soil when you die and being taken up by plants. We’ve taught this in 4th grade, 7th grade and 8th grade. The other was that carbon dioxide TURNS INTO oxygen to be breathed out. Both were surprisingly widespread despite recent instruction and bead games around conservation of matter and the constancy of atoms. I think next year, I’ll separate radioactivity more completely from chemical properties. And try not to be sick for 3 weeks so each concept can be practiced more and taught more slowly!
Testing Acids leading to Ocean Acidification
Today, we tested the acidity of a whole range of household chemicals with universal indicator, including waters – distilled, tap, ‘Instant Ocean’ and soda water. They had to figure out how to make their own data table, how to keep track of what chemical they were testing using the way cool SEPUP trays. Much, much easier than test tubes because they use less chemical and are easier to wash. You can get these from Lab-Aids.
The student sheet 4. Acids Bases pH and oceans lab has teacher notes at the end. This is adapted from www.us-ocb.org and feeds right into the pressing issue of ocean acidification, as you’ll see from the pre-instruction and analysis questions on the sheet.