Tuesday, March 27, 2012

Apple Ring Wrap Up

Remember those apples we had drying on the handy-dandy drying line I strung up behind my desk? We started them on a Wednesday afternoon and by the next Monday morning they were dry, dry, dry and ready to eat. A few kids helped me pull them off on Monday afternoon and we ate them for snack on Tuesday. Kids ate and liked them, but they didn't get rave reviews.

That's okay, because chemistry crept in.

Our chemistry unit is over, but that doesn't mean I won't take an opportunity to remind my class that chemical reactions are continuing to happen around us all the time. In this case, it was the apple bits that weren't big enough to hang on the lines I strung. I spread them out on a baking pan figuring I'd leave them to dry for as long as it took instead of dumping them in the compost.

But there's no way I'm feeding this to my students:

Do you see the dark outline around many of the apple bits? Here, look a little closer:

Some are flipped over, because I showed them to the class and asked what they thought caused the discoloration. Many kids were so sure the apples had molded that they saw fuzziness on the apples that wasn't even there! Some of those same kids had a hard time letting go of their initial hunch, even when I pointed out that the discoloration was on the underside, and if mold had been trying to grow, wouldn't it grow on top of the apple slices? (Although in fairness, if they don't understand that mold would start its growth because of spores that had landed on the fruit, how could they understand my logic?)

I proposed the hypothesis that the apples that touched the pan had reacted chemically with the metal of the baking pan. Color change = indicator of chemical reaction. This got a conversation started about whether apple rings would discolor if we had laid down plastic wrap, tinfoil, waxed paper, etc. I am hoping to get some more apples from our kitchen and set up an experiment just because we could, but we have had art projects and field trips, so the past two weeks have not offered up the time to do so. Luckily, there's always next week. It may have felt like summer last week, but we have many days to go before our year is over.

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