RockLicker · Grade 3 · Lesson 2 of 5

The Settling Jar

Describe sediment settling over time and state a limit to a small model.

  • Grade 3
  • 40 minutes
  • Worksheet + teacher guidance
Back to Grade 3

What you will learn

Particles carried in water can settle when movement slows. Size, density, shape and clumping affect settling; a jar does not reproduce an entire river.

Words to use

  • sediment: loose particles
  • settling: particles coming to rest
  • model: a simplified example

Evidence for this lesson

Supplied observations: at 0 min, sand particles are visible moving through water. At 5 min, much sand lies at the bottom and the water is clearer. Some fine material remains suspended. At 20 min, more material rests at the bottom.

Use the supplied record as written; do not invent missing results.

Work through the activity

  1. 5 min · PredictAn adult prepares the jar over a tray. Predict what you will see immediately after gentle mixing and after it rests.
  2. 10 min · ObserveAn adult gently turns the sealed jar, then sets it down. Sketch at the start and after five minutes. Use supplied observations if a demonstration is unavailable.
  3. 15 min · Compare recordsCompare particle positions and water clarity. Name what changed and what did not. Do not claim that every fine particle will settle within the lesson.
  4. 10 min · Explain limitsDescribe where sediment gathered. State one difference between a closed jar and flowing water outdoors.
RockLicker
GRADE 3 · LESSON 2

The Settling Jar

Draw on the printed sheet or write, type or dictate your response.
Draw on the printed sheet or write, type or dictate your response.
Draw on the printed sheet or write, type or dictate your response.
Draw on the printed sheet or write, type or dictate your response.

Responses stay in this open page only. Print before closing or changing pages; no student record is stored online.

Check your understanding

Sand resting on the bottom after mixing is an example of …

Teacher & family guide · answers and assessment

Grade 3 · The Settling Jar

Learning goal: Describe sediment settling over time and state a limit to a small model.

Expected responses

  1. Any reasoned prediction is acceptable; assess revision after observation.
  2. In the example, particles move through water at first and much sand later rests at the bottom.
  3. Sediment at rest on the bottom is evidence of deposition.
  4. A jar lacks continuous flow, a changing channel and incoming sediment.

Understanding check: deposition. Loose sediment has settled; this is deposition, not evidence that it became rock.

Watch for this misconception

Settling order is not controlled by particle size alone.

Assess the evidence

Look for the observations, calculation or explanation named in the learning goal. Accept accurate drawings and dictated responses. Use the expected responses to discuss reasoning; a correct guess without explanation is a starting point for another conversation.

Adapt and extend

Read prompts aloud, enlarge print or let a partner record the learner’s explanation. Compare five-minute and twenty-minute photographs without making a new jar.