This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Marcus finds a rock with new cracks near a hot desert road, where days are hot and nights cold. This shows weathering by temperature changes because heating and cooling cause expansion and contraction, leading to cracks. The specific evidence of weathering includes: new cracks forming in a setting with extreme temperature swings. For example, the rock develops cracks due to repeated daily heating from the sun and cooling at night. Choice A is correct because it identifies temperature changes as the cause, where repeated heating and cooling made the rock crack, fitting the desert conditions. The observations support this because the hot days and cold nights provide evidence of the agent causing physical weathering in place. Choice B is incorrect because it describes river erosion, involving movement, but here the rock is stationary with only cracks appearing. This error occurs when students don't distinguish weathering (breaking down in place) from erosion (moving materials). The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Keisha sees small rock fragments around a cracked stone after many freeze-thaw cycles. This shows weathering by ice because freezing expands cracks, breaking the stone into pieces. The specific evidence of weathering includes: widened cracks and broken fragments appearing over time. For example, the stone develops cracks that widen and eventually cause pieces to break off, leaving fragments around it. Choice A is correct because it describes the stone breaking into smaller pieces as cracks widened, accurately capturing the effect of weathering. The observations support this because the freeze-thaw cycles connect to ice expansion causing fragmentation in place. Choice B is incorrect because it describes erosion, where the stone is transported away, but here it breaks in place with fragments nearby. This error occurs when students don't distinguish weathering (breaking down in place) from erosion (moving materials). The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Jamal sees a thin crack in a boulder widen after many winters. This shows weathering by ice because freezing water expands in the crack, exerting pressure that widens it. The specific evidence of weathering includes: the crack becoming wider over time without the boulder moving. For example, after several cold winters, the once-thin crack is noticeably larger, indicating repeated freeze-thaw cycles. Choice A is correct because it accurately identifies ice weathering as the agent, where freezing water expands and widens the crack, matching the observation of widening over winters. The observations support this because the timing with winters suggests ice formation, and the boulder remains in place, demonstrating physical weathering. Choice B is incorrect because it describes wind erosion, which involves moving rock pieces away, but here the boulder stays in place with only the crack changing. This error occurs when students don't distinguish weathering (breaking down in place) from erosion (moving materials). The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Chen compares a new and 80-year-old gravestone, noting the old letters are smooth. This shows weathering by agents like water or wind because they abrade and smooth the surface over time. The specific evidence of weathering includes: worn-down letters that are harder to read and smoother surfaces. For example, the old gravestone has smooth, barely visible letters compared to the sharp ones on the new one, indicating long-term exposure to weather. Choice A is correct because it cites the worn-down letters being harder to read, accurately describing the smoothing effect of weathering. The observations support this because the comparison over 80 years shows progressive change in place without movement. Choice B is incorrect because it describes erosion, where the gravestone is carried away, but here it remains in place with only surface changes. This error occurs when students don't distinguish weathering (breaking down in place) from erosion (moving materials). The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Maya sees a tree root in a sidewalk crack that widens over years. This shows weathering by plant roots because growing roots exert pressure, pushing the crack apart. The specific evidence of weathering includes: the crack becoming wider with the root present. For example, the once-narrow crack in the sidewalk is much wider after several years, with the root visibly embedded. Choice B is correct because it identifies root wedging, where growing roots push the crack farther apart, matching the observation of widening over time. The observations support this because the presence of the tree root directly connects to the physical force causing the change in place. Choice C is incorrect because it describes erosion, where the whole sidewalk is moved, but here only the crack changes in place. This error occurs when students don't distinguish weathering (breaking down in place) from erosion (moving materials). The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Sofia notices a rock with orange stains and pitted spots after rainy years. This shows chemical weathering by water because rain dissolves minerals, causing color changes and pits. The specific evidence of weathering includes: orange rust-like color and pitted surfaces indicating mineral breakdown. For example, the rock develops orange stains and small pits where minerals have been chemically altered or dissolved by rainwater. Choice A is correct because it describes the orange rust-like color and pits as evidence of minerals changing and weakening, typical of chemical weathering. The observations support this because the changes occur after rainy periods, linking to water's chemical effects in place. Choice B is incorrect because it describes erosion, where the rock rolls downhill, but here the rock shows color and texture changes without movement. This error occurs when students don't distinguish weathering (breaking down in place) from erosion (moving materials). The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Diego photographs a desert rock yearly, noting small holes growing larger. This shows weathering by wind because blowing sand scrapes and enlarges the holes. The specific evidence of weathering includes: holes becoming larger over time in a windy desert environment. For example, initial small pits in the rock surface expand into bigger holes after years of sand abrasion. Choice A is correct because it identifies wind abrasion, where blowing sand scrapes and wears away the rock surface, matching the enlarging holes. The observations support this because the desert setting with wind-blown sand connects to the abrasion evidence. Choice C is incorrect because it describes deposition, adding material, but here material is being removed to enlarge holes. This error occurs when students confuse weathering with deposition or don't connect specific evidence to agents. The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Yuki watches a pothole grow each winter, with cracks filling with water and freezing. This shows weathering by ice because freezing expands the cracks, enlarging the pothole. The specific evidence of weathering includes: widened cracks and broken pieces after freezing. For example, the pothole starts small but grows with visible cracks and fragments after winter cycles. Choice A is correct because it describes cracks widening after freezing and broken pieces appearing, citing evidence of ice weathering. The observations support this because water freezing in cracks connects to the expansion and growth each winter. Choice B is incorrect because it describes erosion by flowing water moving the road, but here the change is in place. This error occurs when students don't distinguish weathering (breaking down in place) from erosion (moving materials). The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Amir compares 1920 and current photos of a stone statue, noting smoother details today. This shows weathering by rain and wind because they abrade the surface over decades. The specific evidence of weathering includes: smoothed surfaces and less distinct details. For example, the old photo shows sharp features, while today's shows worn, rounded edges from long-term exposure. Choice A is correct because it identifies rain and wind as agents that slowly wore away the statue’s surface, matching the smoothing over time. The observations support this because the comparison across years shows progressive abrasion in place. Choice B is incorrect because it attributes to plant roots carrying it away, confusing weathering with erosion and wrong agent. This error occurs when students don't connect specific evidence to specific agents or confuse with movement. The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.

This question tests 4th grade ability to observe and identify evidence of weathering effects on rocks and land (NGSS 4-ESS2-1). Students must recognize observable changes caused by weathering agents. Weathering is the breaking down or changing of rocks and land in place (not moving materials - that's erosion). Weathering agents include: (1) Water - dissolves minerals, causes chemical changes, (2) Ice - water freezes in cracks, expands, breaks rock apart, (3) Wind - carries sand particles that scrape rock surfaces, (4) Temperature changes - heating and cooling cause expansion/contraction, cracking, (5) Vegetation - roots grow in cracks pushing rock apart, organisms produce acids. Observable effects: cracks forming, surfaces smoothing, sharp edges becoming rounded, rocks breaking into smaller pieces, color changes, texture changes. Weathering occurs over time - from years to thousands of years. In these observations, Fatima sees one rock with orange stains and tiny pits compared to a fresh-looking rock, indicating changes over many years. This shows chemical weathering because water and air react with minerals like iron, causing rust (orange color) and dissolution (pits). The specific evidence of weathering includes: color change to orange and pitted texture without movement. For example, iron-rich rocks develop rusty stains and holes after exposure to moisture and oxygen over time. Choice A is correct because it accurately describes chemical weathering effects as orange staining and pitted surfaces from reacting with water and air, and the observations support this because the changes indicate chemical alteration in place. Choice B is incorrect because it describes erosion by sliding the rock, not chemical changes to color and texture. This error occurs when students don't distinguish weathering (breaking down in place) from erosion (moving materials) / don't connect specific evidence to specific agents / think weathering is instant / confuse human activity with natural weathering / miss observable evidence. The key: Weathering = rocks breaking down or changing in place, and we can observe the evidence (cracks, smoothing, breaking, etc.). To help students observe weathering: Conduct observations - examine rocks near school (smooth vs. angular), old buildings/monuments (worn vs. new), cracked sidewalks (freeze-thaw damage). Compare before/after: new fence post vs. weathered post, new statue vs. old statue with worn details. Identify weathering agent from evidence: cracks in cold climates (ice weathering), smooth rounded river rocks (water weathering), pitted rocks in deserts (wind weathering), rocks split by tree roots (vegetation weathering). Create observation charts: What do we observe? (cracks, smoothing, breaking) → What could cause this? (ice, water, wind, roots) → Is there evidence of this agent? (cold climate, water nearby, wind, plants) → Conclusion: weathering by [agent]. Practice identifying: Show photos of weathered rocks, students identify evidence and agent. Key observations: Cracks = physical weathering (ice, roots, temperature), Smoothing = abrasion (water, wind), Breaking = forces acting (ice, roots), Color changes = chemical weathering (rust, dissolving). Emphasize: Weathering takes time but effects are observable and measurable.