Assignment Task: You will need these materials:
1 small balloon
1 cup of plaster of Paris
16-ounce freezer-safe plastic container
8-ounce plastic cup
Water at room temperature
2 effervescent antacid tablets
Stopwatch or timer
Knife or metal spoon
Question: Hypothesis and Data Collection
Fill the balloon with water until it is the size of a golf ball, and tie a knot in the end. Make sure there are no air bubbles in the balloon. In the plastic container, mix the plaster of Paris powder with water until it is as thick as yogurt, and then press the balloon into the center. One-third of the balloon should be below the surface of the plaster. Set the container aside until the plaster sets.
Part A:
In this experiment, you will place the container in the freezer. What do you think will happen?
In this next experiment, you'll use effervescent tablets to represent rocks. Dissolve one tablet whole and another tablet cut up (or broken up) into small pieces. Write down your predictions about how fast you think the whole and broken tablets will dissolve in room-temperature water.
Fill the plastic cup half full with room-temperature water, and drop in the whole tablet. Use a stopwatch to measure how long it takes the tablet to dissolve completely. Record your observation.
Wash out the cup and fill it half full of room temperature water. Use a knife to cut the other tablet into tiny pieces, or firmly tap the tablet with the back of a metal spoon to break it up. Add the pieces of the broken tablet to the cup of water. Using a stopwatch, time how long it takes for the tablet to dissolve completely. Record your observation.
Did your predictions match your observations for the plaster of Paris experiment?
Did your predictions match your observations for the effervescent tablets experiment?
Which experiment symbolized mechanical weathering of rock and which symbolized chemical weathering? Explain your answer. Need Assignment Help?
What types of geologic processes cause the types of weathering that occurred in your experiments?
How do your experiments relate to the geologic processes that form soil?
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