Irene Finch, in her 1971 book Nature Study and Science, identifies the problems with the candle in the jar activity, and points out that children have many explanations, but that the candle does not go out because all the oxygen is used up. Some Year 6 children germinated seeds and rusted nails in jars for me after the candle had gone out, which would have needed some oxygen.
The tongue area and taste activity has been in many textbooks. It never seems to work. Recent research suggests that the differences in taste sensitivity between individuals is enormous; so if children tell you that sprouts, liver or eggs taste disgusting to them, they may well be telling the truth.
I'm interested in examples of other dead-loss primary science activities that have been copied from book to book without practical testing. Do let me know of any that don't work for you.
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