NZ Things

My boy has been fascinated by volcanoes lately thanks to the Auckland Museum’s interactive display. He has Robin Kerrod’s excellent book on Volcanoes and Earthquakes out on permanent loan from the school library and has been working through the experiments.

Last night we played geysers but the winner so far has been the Carbon Dioxide Candle Killer.

I grabbed one of my expensive Tupperware oil bottles and sellotaped a drinking straw to the end and let the kids put a small amount of baking soda and vinegar in the bottle. Instant froth and even though there was no wind sensation of gas escaping the straw when you placed the straw next to a candle there was enough impact to immediately put out the candle.

Very impressive.

BTW: Kerrod recommends a normal bottle with a play dough seal and a straw poked through.

Ofcourse now we have discussions about poisonous gasses, how much carbon dioxide is too much, how come rescitation works and how good it is that the trees clean our air.

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