Lesson 2: Developing Constructive & Destructive Forces Models
Weathering, Erosion, and Deposition
Grade 5 • Georgia Standards of Excellence — S5E1.b • 50 minutes
Focus: Explain how weathering (breaking), erosion (moving), and deposition (dropping) change Earth’s surface.
- I can tell the difference between weathering, erosion, and deposition.
- I can describe how water, wind, and ice change land over time.
- I can use evidence from a model to explain how to slow erosion.
- Shallow tray or baking pan (1 per group)
- Play sand or dry soil (about 3–4 cups)
- Cup or beaker (250 mL)
- Water
- Plastic spoon or small scoop
- Ruler
- Small pebbles/blocks (to act as rocks)
- Piece of felt/grass mat or paper strips (to model plant roots)
- Straw or small fan (to model wind)
- Paper towels
- “Erosion and weathering are the same.” (Weathering breaks rocks; erosion moves the pieces.)
- “Deposition means no change.” (Deposition adds new land like deltas and sandbars.)
- “Plants cause more erosion.” (Plant roots usually reduce erosion by holding soil.)
Engage 5 minutes
Bell Ringer — Milestones-Style
A river carries tiny pieces of rock and drops them where the river meets the ocean. Over time a fan-shaped landform grows. What process is this?
A Weathering
B Erosion
C Deposition
D Condensation
Discuss your choice with a partner. Be ready to share one clue from the question that helped you decide.
Teacher Demo 5 minutes
- Hold a cup with a small hole poked in the bottom over a tray filled with sand shaped into a small hill.
- Pour water in the cup to make a light “rain.” Watch the sand move down the slope.
- Ask: What is breaking the sand? What is moving it? Where does it pile up?
Talk Moves
- Weathering = breaking apart.
- Erosion = moving pieces.
- Deposition = dropping pieces to make new land.
Quick Sketch
Explore — Hands‑On Lab (Student Groups) 20 minutes
Question: How do water, wind, and plants change the shape of land?
Set Up (per group)
- Fill the tray with sand/soil. Build a short slope on one side. Leave a flat area at the bottom.
- Place a few pebbles on the slope to act like rocks. Put the felt/paper strips on half of the slope to model plant roots.
- Label the flat area “river/ocean.”
Tests (run two or more)
- Water Flow: Slowly pour 1 cup of water from the top of the slope. Observe paths and where material piles up.
- Plants vs. No Plants: Repeat, but compare the side with felt/strips to the bare side.
- Wind: Gently blow across the slope with a straw or small fan for 10 seconds.
Record Data
| Test | What We Changed | What Moved? | Where Did It Pile Up? | Process Seen |
|---|---|---|---|---|
| Water Flow | Added water from top | ____________________ | ____________________ | Weathering / Erosion / Deposition |
| Plants vs. No Plants | Roots on one side | ____________________ | ____________________ | Weathering / Erosion / Deposition |
| Wind | Blew air for 10 s | ____________________ | ____________________ | Weathering / Erosion / Deposition |
Draw Before
Draw After
Claim–Evidence–Reasoning
Claim: ____________________________ reduced erosion the most.
Evidence: _________________________________________________
Reasoning: _________________________________________________
Explain 10 minutes
Key Ideas
- Weathering breaks rock into smaller pieces.
- Erosion moves rock and soil by water, wind, or ice.
- Deposition drops the material and builds new land.
- Plants help hold soil. Slower water drops more sediment.
Cause & Effect Chain
- Rain hits a slope and loosens soil (weathering).
- Water carries soil downhill (erosion).
- Water slows on flat ground and drops soil (deposition).
Elaborate 5 minutes
Choose one real place and explain which process is strongest there:
- Barrier islands on the Georgia coast
- Banks of the Chattahoochee River
- A windy sand playground
Write 2–3 sentences naming the main process and one way people can slow erosion or protect land there.
Evaluate — Quick Checks (Milestones Style) 5 minutes
- Multiple Choice: Which action would most reduce erosion on a school hill?
A Plant grassB Remove rocksC Add more waterD Sweep away leaves
- Multi‑Select (choose two): Which are examples of weathering?
A Ice cracking a rockB River carrying sandC Acid rain wearing limestoneD Sandbar growing at a river mouth
- Data Read: In a lab, “No Plants” moved 8 spoonfuls of soil; “With Plants” moved 2 spoonfuls. What is the best claim?
A Plants increased erosionB Plants reduced erosionC Water had no effectD Wind caused deposition
Exit Ticket — 5 Questions (Milestones Style)
- Which process builds a delta?
A WeatheringB ErosionC DepositionD Melting
- A student pours water down two trays. Tray 1 is bare soil. Tray 2 has felt strips like roots. Which tray will lose more soil?
A Tray 1B Tray 2C Both the sameD Neither
- Choose the sentence that best describes erosion.
A Rocks break into sandB Wind carries sand across a beachC Mud piles up at the end of a streamD Lava cools into rock
- Multi‑Select (choose two): Which changes are mostly caused by deposition?
A Sandbar formingB River cliff getting steeperC Delta growingD Rock cracking in winter
- Short Response (2–3 sentences): Explain how weathering, erosion, and deposition worked together in your lab today.
Answer Key — Exit Ticket
- C — Deposition builds a delta by dropping sediment.
- A — The bare soil tray loses more soil.
- B — Erosion is the movement of rock/soil by wind, water, or ice.
- A and C — Sandbars and deltas form from deposition.
- Sample: Rain broke soil into small pieces (weathering). Water carried the pieces down the slope (erosion). The water slowed on flat ground and the soil piled up into a new layer (deposition).