1. Gather materials and make copies of the Erosion Worksheet.
2. Set up five stations, and disperse the materials to the correct station.

• Make sure to label the rock samples for the chemical erosion station.
• Make sure to place soil in the container for the water erosion station.
• Make sure to set up a pile of sand in the large box or outside for the sand erosion station. Note: Place the fan far enough away from the sand so that it will not blow it all over the place. (The idea is to move a layer of sand from the center, to the another side of the box; gradually moving the entire "sand dune.")

Station 1: Chemical Erosion Station

1. Take one of the rocks and place it in the glass tray.
2. Slowly add drops of lemon juice/vinegar to the rock using the eye dropper.
3. Observe the rock with the magnifying glass.
4. Record your observations on your Erosion Worksheet. (Specifically, did the rock bubble when you placed the weak acid on it?)
5. Discuss with your partners why you think such a reaction occurred.
6. Remove the rock, dry it off, and set it off to the side of the rest of the rocks.
7. Pour out any liquid from the glass tray into the sink.
8. Repeat steps 1-7 with all the remaining rocks.

Station 2: Water Erosion Station

1. In a large container, form a mountain of soil about 3 inches across (wide at the top) and about 5 or 6 inches tall in the container.
2. Press the coins/chips into the surface of the dirt/clay. (Place them at different angles with the edge protruding out; leave about half the coin showing.)
3. Create a rainstorm by pouring water on the mountain with the watering can.
4. Record your observations. (Are the coins sticking out more or less? What does the bottom of the mountain look like?)
5. Remove the coins and put them back onto a paper towel to dry.
6. Drain the water into a sink.

Station 3: Wind Erosion Station

1. Form a pile of sand in the center of the box (approximately 5 or 6 inches tall).
2. Using the fan, blow air lightly over the sand from one end of the box to the other.
3. Record your observations. (Did the pile of sand move?)

Station 4: Glacier Erosion Station

1. Take a ball of clay from the container (approximately 1-2 inches in diameter).
2. Flatten the clay onto the surface on the tray.
3. Press an ice cube against the flattened clay and move it back and forth several times.
4. Record your observations. (Does anything happen to the clay when you rub the ice cube on it?)
5. Place a small pile of sand on the clay and then place the ice cube on top of the sand for 1-2 minutes.
6. Pick up the ice cube and observe the surface of the cube that was touching the sand and record your observations. (What does the bottom of the ice cube look like?)
7. Place the same side of the ice cube on the sandy part of the clay and move it back and forth several times.
8. Remove the ice cube and wipe away the sand from the surface of the clay.
9. Record your observations. (What does the texture of the surface of the clay feel like?)
10. Place the clay back where it came from and throw away the remaining ice and sand.

Station 5: Temperature Erosion Station (this station should be used as a demonstration or done with an adult helper)

1. PUT ON SAFETY GOGGLES!!!!
2. Use the tongs to place the marble into the beaker.
3. Turn the burner on about ¾ of the way.
4. Leave the marble in the beaker for 5 minutes.
5. While you are waiting, make sure you have enough water in one beaker and ice in the other beaker.
6. After 5 minutes have passed, turn off the burner.
7. Use the tongs to place the marble briefly into the water and then into the beaker of ice.
8. Look at the marble and record your observations.
9. You may now take off your safety goggles.

Discussion Questions: Solicit, integrate and summarize student responses.

• Do you know what erosion is?
• What is an example of erosion that you have seen in nature?

Worksheet: Have the students record their observations on the Erosion Worksheet; review their answers to gauge their mastery of the subject.

Problem Solving: Present the class with the Erosion Math Worksheet and ask the students to calculate the effect of erosion in each of the scenarios. Discuss how engineers might need to solve similar problems when working to protect the environment, structures, landmarks and people's lives.

Define It! Drawing: Have students draw pictures of each of the five types of erosion that were discussed and write their own definition of erosion (and its effects) at the bottom of the page.