Jun 30, 2011

rugby wold cup

Jun 29, 2011

How Popcorn Pops

Are you ever wondering how popcorn pops?  First you put some kernels  in a pot.  Then use a hot plate and turn it on.  When the water in the kernel turns into steam, the steam pushes the shell of the kernel and it explodes. There you have popcorn!

So now you know how to make popcorn.

Why does popcorn pop?

Jun 28, 2011

Popcorn

Jun 22, 2011

Let's Make Ice Cream!



Photos taken by Michael!

Jun 21, 2011

How to Make Ice Cream!

What you'll need:
2 tablespoon sugar
1 cup milk or half & half
1/2 teaspoon vanilla
8 tablespoons rock salt
1 large plastic food storage bag (e.g., Ziploc) 
1 small plastic food storage bag
Ice cubes

How to make it:
Fill the large bag half full of ice, and add the rock salt. Seal the bag.
Put milk, vanilla, and sugar into the small bag, and seal it.
Place the small bag inside the large one, and seal it again carefully.
Shake until the mixture is ice cream, which takes about 5 minutes.
Wipe off the top of the small bag, then open it carefully. Enjoy!


Why does this happen?

Ice has to absorb energy in order to melt, changing the phase of water from a solid to a liquid. When you use ice to cool the ingredients for ice cream, the energy is absorbed from the ingredients and from the outside environment (like your hands, if you are holding the baggie of ice!). When you add salt to the ice, it lowers the freezing point of the ice, so even more energy has to be absorbed from the environment in order for the ice to melt. This makes the ice colder than it was before, which is how your ice cream freezes. Ideally, you would make your ice cream using 'ice cream salt', which is just salt sold as large crystals instead of the small crystals you see in table salt. The larger crystals take more time to dissolve in the water around the ice, which allows for even cooling of the ice cream.

Have a look at this video that compares a normal melting ice cube with an ice cube that has salt sprinkled on it. Which melts faster?

Te Tae - Colours

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