Matter Clues from Evidence

Overview

In this lesson, students use observations to decide whether everyday materials are solids or liquids. They learn that observations are evidence when they are accurate, recorded clearly, and used to support a reasoned conclusion.

Learning intentions

• Students will observe materials carefully and record what they notice using accurate measurement words and descriptions.
• Students will explain how particle modelling helps us understand why solids keep their shape and liquids flow.
• Students will use observation evidence to decide whether a material is a solid or a liquid.
• Students will compare their method and findings with classmates to identify possible sources of error.

Success criteria

• I can describe observations that show whether a material keeps its shape (solid) or flows (liquid).
• I can record evidence in a clear table (material name, test result, and my conclusion).
• I can justify my conclusion using the evidence from my observations.
• I can suggest at least one reason a result might be unreliable (error).

Curriculum links

• Science Understanding: observable properties of solids and liquids can be explained by modelling the motion and arrangement of their particles.
• Science Inquiry: identify sources of error and use evidence to support reasoned explanations and conclusions.
• Science Inquiry: plan repeatable investigations by choosing variables to be changed, measured and controlled for fair tests.
• Science Inquiry: use investigable questions and reasoned predictions to guide investigation.

Lesson structure (40 minutes)

1. 0–5 min · Hook and question. Teacher shows two cups: one with water and one with rice (or sand) and asks: “What observations would count as evidence to tell us which one is a solid and which one is a liquid?” Students do a quick think-pair-share.

2. 5–12 min · Mini direct teach: observations vs conclusions. Teacher models a “good evidence” sentence: “I observed ___, so I conclude ___.” Teacher links to particle modelling: solids have particles arranged in place so they don’t flow; liquids’ particles can move past each other so they flow. Students turn and talk: “What observation would be strongest evidence?”

3. 12–18 min · Plan the test (fair and repeatable). Teacher introduces the investigation routine. Students help fill a class checklist for a fair test: same container size, same amount by volume (e.g., spoonfuls measured by a scoop), same tilt angle/time, and observe for shape change and flow. Students make a reasoned prediction for 1 teacher-demonstration material (“solid because…” or “liquid because…”).

4. 18–31 min · Investigation rotation: evidence collection. In groups, students test 4–6 unknown materials using the agreed procedure (e.g., pour/tilt test into a shallow tray, observe whether it keeps a shape or flows, and check if it can be poured into another container). Teacher circulates using prompts: “What did you observe? What is your evidence? What is your conclusion?” Students record observations in a table:

• Material
• Observations (shape, flow, how it behaves when tilted/poured)
• Evidence words (kept shape / flowed / formed a puddle / ran)
• Conclusion: solid or liquid
• Confidence: high/medium/low (why?)

5. 31–37 min · Comparing findings and identifying error. Teacher brings class back. Each group shares one material result. Teacher asks: “Did any group see something different? What source of error could explain that?” Possible errors include spills, different amounts used, not waiting long enough, containers tilted at different angles, or mislabelled samples. Students revise one evidence claim if needed.

6. 37–40 min · Exit ticket (quick assessment). Students answer:

• “Write one observation that is strong evidence for a liquid.”
• “Write one observation that is strong evidence for a solid.”
• “Name one possible source of error in testing.”

Resources

• A set of unknown materials (common, safe choices): water, oil (if used per school safety), coloured water, sand, rice, flour, moisturised soil (if permitted), small beads (as “solid”), and/or gel for liquids depending on safety policies
• Shallow trays or basins and small cups/containers for testing
• Spoons/cups/scoops to keep amounts consistent
• Measuring cups or marked containers (for volume by scoop)
• Recording sheets with an observations/evidence/conclusion table
• Lab towels and a “spill plan” (bin for waste, quick wipe cloths)
• Whiteboard and markers
• Safety glasses (if required by school policy) and gloves if handling oils or messy substances

Assessment

• Formative during investigations: teacher checks students’ observation wording (“kept shape”, “flowed”, “piled”, “puddled”) and whether conclusions match evidence.
• Formative during group sharing: students identify at least one source of error and explain how it could affect reliability.
• Summative check via exit ticket: evidence-based sentences for both solids and liquids plus one error source.

Differentiation

• Support: provide sentence starters on the recording sheet (e.g., “I observed ___ which shows ___.” “This is evidence of a ___ because ___.”).
• Support: model one group’s recording on the board before students begin; allow students to use icons for flow/shape if needed.
• EAL/SEN: offer a word bank for evidence language (kept shape, flowed, ran, poured, puddle, pile, takes the container shape). Allow oral recording into a template if writing is a barrier.
• Extension: challenge students to write two alternative explanations for one result (e.g., “If it looked mixed, how might that change our conclusion?”) and then select the most evidence-supported one.