General Science: It's a Gas!

For our experiment this week, we did an oldie but a goodie...what happens when you mix baking soda and vinegar?

Having some experience with making volcanoes or otherwise messing around in the kitchen, the kids guessed correctly that the combination would produce, in their words, "AN EXPLOSION!!!" (Aren't you glad this happens at my house and not yours?!)

This week we took it one step further to show that the combination of baking soda and vinegar produces a gas that can put out a fire. Passing a lit candle over baking soda had no effect on the flame. Same deal for the vinegar, but when you combine the two, and you get your EXPLOSION (i.e. bubbles), passing the candle over extinguishes the flame. Why does this happen? Mixing baking soda and vinegar is a chemical reaction, and as such, produces something new, carbon dioxide. That's what the bubbles are, and they have the property of putting out a fire and that's why they carbon dioxide in an actual fire extinguishers. Cool, huh!?

Biology: Carbon

This week we talked about carbon and how its atomic structure gives it so much versatility in forming chemical bonds with other elements. Using the latest in electron microscopy we were able to produce this incredible image of an actual ethane molecule.

Next time we meet we'll investigate the major carbon-containing macromolecules that make up all living things.

General Science: What to feed your pet yeast

Before we do away with all of our חמץ, it seems appropriate to learn something about our tiny unicellular fungal friend, the yeast. After all, we have a lot in common: Like us, yeast eat, reproduce, and respire. That's fancy-talk for releasing carbon dioxide as a result of transforming the energy from food into energy our cells can use. This comes in handy when baking bread. It's the carbon dioxide gas that causes the bread to rise.

This week's question was: What's a yeast's favorite food: salt, sugar, or flour? To know which food was eaten most heartily by our yeast, we prepared bottles of yeast, warm water, and one of the three foods being tested. We covered each bottle with a balloon and then sat back and watched the show. The samples of yeast fed sugar were the happiest, i.e. the balloons inflated the fastest because of the greater production of carbon dioxide. Flour came in second and salt came in last. We discussed how flour, a complex sugar, gets broken down into simpler sugars. A little more work, but when you're hungry, you do what you have to. Yet one more thing we all have in common...LAZINESS and an appreciation for fast food.