Children can learn about the rock cycle through an experiment.
Although rocks are non-living things, they have the ability to change and go through a cycle. Rocks begin their cycle as an igneous rock. Over time, the igneous rock changes to a sedimentary rock. More time passes, and the sedimentary rock turns into metamorphic rock. Eventually, the metamorphic rock changes and becomes either an igneous or a sedimentary rock. Teachers can demonstrate the rock cycle with a classroom activity.
Preparation
Clear off a desk and lay down a few sheets of newspaper to protect it from becoming marked and dirty. Gather several yellow and red crayons, a kitchen knife, aluminum foil, a hammer, a candle, matches, a pair of tongs and a set of plastic gloves for each student who is going to help with the activity. Set these items on the desk. Discuss the rock cycle with the children before beginning the activity, so they will understand what is happening.
Igneous to Sedimentary
Tell the kids to pick up the yellow and red crayons. Explain that these crayons represent igneous rocks. Ask two students to shave a yellow and red crayon with the kitchen knife. Tell the students that weather, such as wind and rain, causes pieces of the igneous rock to break off. Other rocks may also rub up against the igneous rock causing it to break apart. Get another student to take some of the yellow shavings and some of the red shavings and mix them together, pressing them so that they stick together. This occurs with the pressure of erosion. Sedimentary rock is then formed as a result of the erosion. Set the newly formed sedimentary rock on two sheets of aluminum foil.
Sedimentary to Metamorphic
Find another student volunteer, and ask him to make a packet out of the aluminum foil. Enclose the sedimentary rock inside the aluminum foil. Instruct a different student (you want each student to have a chance to participate) to hammer the sedimentary rock to demonstrate the pressure that occurs when several sedimentary rocks lie on top of each other. Open the aluminum foil packet to see the newly formed metamorphic rock. The metamorphic rock will be stronger than the previous sedimentary rock, as it hardens under pressure over a period of time.
Metamorphic to Igneous
Ask another student to re-wrap the metamorphic rock in the aluminum foil. Hold the packet with a set of tongs, and place it over the flame of a burning candle. Hold the packet over the flame for a total of one minute. Explain that metamorphic rock is heated during a volcanic eruption. Remove the packet from the heat and give it time to cool off, as a metamorphic rock would after a volcanic eruption is over. Instruct one final student to open the aluminum foil pack, and pick up the newly formed igneous rock. Give the kids a chance to feel the igneous rock. It will feel the same as the crayons they first picked up when they began the activity. Review that the cycle would start over again if any of the students took the kitchen knife and begin shaving this igneous rock.
Tags: aluminum foil, igneous rock, metamorphic rock, sedimentary rock, another student, kitchen knife
