So we got round to it. After a little review (20 minutes or so) of what happens when you add bicarbonate of soda to vinegar, we knocked up some purple cabbage juice in the blender and applied it to various substances. The results:
- Our water is distinctly alkaline,
- You can make all kinds of pretty colours with this stuff,
After that, the chemistry lesson slowly merged into full-blown potions lab…
During which we discovered that kitchen towel is so incredibly alkaline that it turns the cabbage juice a pretty cyan.
I have also learned a couple of things lately. The first and most important is that I’d really better review my chemistry before I teach it. They’ve changed one or two little things in the last 25 years (darn ’em). The other is that anthropomorphic explanations trap ideas in the six-year old mind like honey traps flies: all those mean hydrogen ions zooming around like pirates looking for electrons to steal, whilst the wretched alkalis have more than they know what to do with. Antonia: ¨I bet they’re glad to get rid of them really!¨
I love to see pictures of happy kids doing experiments. 🙂
My daughter called me to the kitchen the other day. She had put a mixture of root beer and Baking Soda into a small testing tube and was excited about the growing, the foam, the mess… I was too, so we added a few other things that we have in the kitchen and watched as the mixture turned funny colors and finally ended up shrinking. Why on earth did I forget to take pictures?