Mechanical and Chemical Weathering

Mechanical Weathering Experiment via Mini Me Geology
materials:

Plastic Wrap

Clay

Water

1. Moisten the clay with a little bit of water

2. Divide the clay into two equal pieces and roll it into a ball or form into a square.

3. Wrap both pieces of clay in plastic wrap.

4. Place one piece of clay into the freezer overnight and leave the other piece out at room temperature. 

5. The next day, take the clay out of the freezer and unwrap both pieces. 

"Do the clay pieces look different?  If so, how?  Hint:  the clay from the freezer should have the some cracks.  Examine the clay with a hand magnifier to get a closer look at the cracks."

"Then, wrap each clay piece back up and put the one piece back into the freezer and repeat for several days.  Observe the clay pieces each day and see how the cracks change over time."  

For more great rock experiments, visit Mini Me Geology!

Chemical Weathering Experiment: Fizz Acid Test on Limestone via ehow
How does acid rain effects rocks? Put a piece of limestone in a cup of vinegar and watch it bubble. "Sediment will form at the bottom of the cup representing the erosion of rock."