Tuesday, April 19, 2011

Rock Cycle.

The boys holding their foil "rock" packets over the candle flame to convert the metamorphic rock into an igneous rock.

Little man is standing on the top board to change his sedimentary rock into a metamorphic rock (him standing on the board signified the pressure that metamorphic rocks undergo). The "big" little man is lighting one of the candles for the next stage.

The packet of crayon shavings, er "sediment," was placed between 2 boards, then the boys pounded the top board with a hammer to cement the layers together to make their sedimentary rock.

D - pounding away to create his sedimentary rock.

I have to admit that projects like this make me love homeschooling even more! It is SO much fun doing an activity with my boys and then seeing the light come on for each of them as they are bettering their understanding of a given subject. In this instance, we were studying rocks and minerals. What better way to learn about the rock cycle than actually participating in an activity that illustrates a concept that seems abstract on paper.

To prepare, I shaved crayons with my dad's old Boy Scout knife--we used 4 or 5 different colors (honestly, I probably only used 4...by the time I got to the last color of crayon, I was ready to be done). The boys both gave me a few crazy looks, then looked at each other to communicate in a way that only two brothers who are best friends can only understand--"Mama is at it again...here she goes with another crazy project!" ;-) This project was surrounded by much intrigue. After all, how often do my boys see their mama break out a pocketknife to shave crayons? I would have had them do the dirty work if we would have had a regular crayon sharpener.

After I finally finished shaving crayons, we drew a 4 cm x 4 cm square onto a piece of aluminum foil, they layered crayon shavings, one color at a time, onto their square, we folded the foil into a little packet, then were off to the garage in search of a hammer and 2 boards. The hammer and boards were found in short order, then the boys took turns hammering their crayon "sediment" packets that were placed between the two boards. One of the crayon sedimentary "rocks" broke, so we could actually see the different colored layers--it was really neat to see! After they inspected their rocks, they put the packet back between the two boards and stood on it to add pressure to the "rock." We discussed what we read in The Magic School Bus: Inside The Earth about metamorphic rocks being created by heat and pressure being applied to an existing rock. Once they inspected their pressurized rocks, they were impressed by how much more compact it was.

The final step was to hold the foil packets over a candle flame to melt the "rock" and then to let it cool to form an igneous rock. We clipped clothespins to the corner of our packet so our hands were further away from the flame. There was a time where the packets also rested on the lip of the candle. Be careful with this step--if you don't have a tight seal on your foil packet, or if holes or tears have been made to the packet during the sedimentary or metamorphic rock phases, hot wax will flow out, I repeat, hot wax will flow out if you are not careful.

I hope that you enjoyed a little glimpse into one of our many fun school projects! :)

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