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.

Here’s how the class room was organized. Worked pretty well, efficient, got through lots of tests quickly. It was very fun.

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.

Collecting gas from a burning coal:

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.

It was a wild day and I’ve only just finished fishing melted chocolate chips out of the sinks, I’m tired but see for yourselves the enthusiasm of my normally cool 8th graders – I think they get the difference between physical and chemical changes, plus a nice intro to acid/base reactions.

Here’s the sheet we used: 1 The Pancake Lab Phys Chem changes with the recipies and ‘The Science of Pancakes’ from “Cook’s Illustrated Magazine”

Day 1: Have students sort Concept Construxion cards by chemical vs physical changes, chemical and physical properties. Nice review of conductivity and of density by the way.

Show the beautifully produced 5minute video clip from NBC Learn chemistry series. Then demo the individual parts of the recipe.

Day 2: Pancake day! Think tiny little frying pans over bunsens. Sweet.

I thought about how to manage all the equipment, the fire and burn dangers, the mess and stickiness ahead of time and still had to perfect it over the day. But no one got burned, no one died and the superintendent and the principal visited and I still have my job.  If you want help with how to set up and safety, let me know and we’ll chat.

Here’s some pics for the general idea:

H added chocolate chips, what an idea – kids brought them in by themselves. Next year that’ll make it easier and amazingly delicious.

Making syrup at the syrup station – the stickiest place in the universe by now.

S is inspired by this lab and wants to do more stuff like this at home. She’s a chef of tomorrow, and maybe SC too.

Just deserts. I’m hungry, time for dinner.