Wednesday 25 February 2009

Science

MOLD
I blogged about our mold experiments a few weeks ago. We were taken aback by how slow it took for the four samples of bread to start to go moldy - close to 2 weeks. Can only assume that shop bought sliced bread has plenty of preservatives in it! The winner in this experiment was the slightly wet bread in the understairs (i.e. dark) cupboard. Once the mold took hold, there was no stopping it! The other examples were still pretty edible I guess, although a couple had gone a little hard around the edges. The overall winner for keeping fresh - in the fridge of course!

However, our experiment of putting a number of small bits of foods in a sealed glass jar has not produced a single bit of fluff, fur, green or anything. It's now been 3 weeks and they still look perfectly OK. I thought the cheese would have shown some signs if nothing else.

In our house, the best producer of mold is my old ice cream container which I keep for scraps and teabags for the compost. Chuck orange peel or the ends of a cucumber in there and they go gooey and moldy pronto because it's wet, dark and warm. That probably would have been the best thing to study!

WATER
We also did some ice and water experiments mainly as a lead up to our HE group 2 session this week on this very topic.

We discovered, thanks to Krampf, that water is quite amazing and is the only common substance that can be shown in three states - liquid, solid and vapour. With help from Krampf and my Usborne 100 Science Experiments, we looked at why ice floats, how to make it melt quickly and how it expands when it's frozen. We also produced a refreshing glass of fruity ice slush with the help of a bowl of ice cubes, salt and an hours worth of stiring (remember Slush Puppy?).
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At our HE group 2 session, Katie and Ben helped demonstrate how to filter dirty water to produce clear, "clean" water. I must admit, in the 3 1/2 years of HE this has to be one of the best science experiments we've ever done (making firework colours is pretty good too). It kept us all focused for so long. You can find it here - it's well worth doing.

Katie and Ben also made magnifying glasses by pouring a small amount of water into a loosely secured clingfilm lid placed over the top of a cut Pringles container.
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