Archive for April, 2011
What do kids REALLY think about how carbon cycles through us all? A test reveals some persistent mis-understandings. And acid tests reveal the pH of all kinds of chemicals, leading into ocean acidification. Student sheets and pics provided 🙂
C + O2 -> CO2, right? No problem.
Using bromothymol blue to see if the collected gas is carbon dioxide.
And we are always safety-conscious:
But some students didn’t realize that the atoms themselves re-arrange and are the SAME atoms that just change their bonds from one side to the other side of the equation and IN REAL LIFE too, that chemical reactions conserve matter. They can slide by with memorizing and learning the ‘turn-the-crank way to balance equations well enough to do okay on the state tests (in OMG 2 weeks…). But they really needed time to think about what was going on at the atomic and molecular level. So glad I cancelled the lab and took this slowly.
It’s kind of fun too, using white boards and markers, working together and ooh, bright, clinky counters. I had no idea that $7 of vase stones from the craft shop would be my best learning tool all year.
The conservation of matter, of atoms, in a chemical reaction is a profound law of the universe – it’s why they are stardust, how we are all connected with the earth and sky, and why we all contain bits of carbon that were once part of Einstein, or Marilyn Monroe. The carbon emphasis on the lab sheet: 3. Investigate chemical reactions stochiometry makes the connection to the Problems with Oil and the Great Carbon Race that has woven through this year’s curriculum and through 7th grade life science too. It’s a really nice realization, an ah ha moment with a little fizz of awe and wonder at the universe.
After letting them have some time to think through the methane + O2 reaction, I had students share their thinking.
And finally, shock, horror…
They did the chapter in the text to consolidate what they were learning.
Try something new and get insights into being a learner, as well as having a fear and fun-filled experience!
Using America’s Test Kitchen recipies, bunsens and tiny frying pans, we hammered (battered?) home the essential differences of chemical vs physical changes with no burns or deaths but alot of stickiness.
Book-ending Atomic Structure with the question “Atomic Energy – the way of the future?!” Today, we wrap it up now we know something about alternative and current energy sources with a game and Concept Connexion cards
Not enough time to plan the action! The gold in the rush…