We made different models in class to demonstrate different kinds of rocks.
Our group made rice krispie treats, which were an example of sedimentary rock. Sedimentary rock is a rock that is formed by a bunch of sediment, a bunch of particles, stuck together. This is the same as rice krispie treats, how the bunches of rice krispies stick together.
The food example of igneous rocks were the seafoam and peanut brittle. The ingredients to make these candies are the same, but the difference in the candy comes from how they cool (just like igneous rocks!). The seafoam demonstrates intrusive igneous rocks, cooling at a slower rate so there is crystallization. Peanut brittle is formed by the sugar cooling very quickly, which makes the shiny brittle candy, just like extrusive igneous rocks.
The butterfinger candy bars that we looked at were an example of metamorphic rocks. One of the best indicators that a rock is metamorphic is that they are foliated, they have these tightly packed layers. If you look at the inside of a butterfinger, the candy has these compact layers, just like metamorphic rocks.
Who knew learning about rocks could be so delicious!
Tuesday, February 22, 2011
Wednesday, February 16, 2011
Mixtures & Bonds
Mixtures - a mix of two substances that are mixed together but not combined chemically. The ingredients can be removed from the mixture afterwards.
Bonding - when the atom in separate things mixed together form chemical compounds, where the electrons are shared, and they become something different than the initial ingredients added.
We did an exercise in class where we did two different kinds of experiments. To examine mixing, we combined cornstarch and water. While the cornstarch and water mixed together and became thicker and harder, it was still just a mixture, and nothing chemically happened. To examine bonding, we mixed Elmer's glue with hot water, shook it for a while, and then mixed in a powdered borax soap. It became this flubbery glue - obviously a chemical change happened.
We realize that once the water has evaporated from the cornstarch solution, we can see the cornstarch in the glass. This is part of the mixture, you can separate the ingredients. We will never be able to pull the Elmer's glue back out of the goop that we made, therefore, a bond happened.
Bonding - when the atom in separate things mixed together form chemical compounds, where the electrons are shared, and they become something different than the initial ingredients added.
We did an exercise in class where we did two different kinds of experiments. To examine mixing, we combined cornstarch and water. While the cornstarch and water mixed together and became thicker and harder, it was still just a mixture, and nothing chemically happened. To examine bonding, we mixed Elmer's glue with hot water, shook it for a while, and then mixed in a powdered borax soap. It became this flubbery glue - obviously a chemical change happened.
We realize that once the water has evaporated from the cornstarch solution, we can see the cornstarch in the glass. This is part of the mixture, you can separate the ingredients. We will never be able to pull the Elmer's glue back out of the goop that we made, therefore, a bond happened.
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