Evaporation Project Planning

Overview

This lesson is lesson 7 of 8 in the unit “Exploring States of Matter”. Students will plan a small, repeatable investigation/project to reduce evaporation in a local water source, using particle ideas to explain why evaporation happens and identifying fair-test variables. They will also discuss engineering challenges and constraints that affect what solutions are feasible.

Learning intentions

Students will:

• Plan a science project using an investigable question related to evaporation and water loss.
• Decide which variable to change, which to measure, and which variables to control for a fair test.
• Describe evaporation in terms of particles moving from liquid to gas when exposed to air.
• Develop a feasible solution and explain trade-offs (materials, safety, practicality, maintenance).

Success criteria

Students can:

• Write a clear investigable question and reasoned prediction about reducing evaporation.
• Create a method that identifies one variable changed, one measured, and key variables controlled.
• Produce a feasible solution design (what will be used, where it will go, how it will be tested).
• Explain at least one engineering challenge and how their plan addresses it.

Curriculum links

• AC9S5U04: explain observable properties of solids, liquids and gases by modelling the motion and arrangement of particles (evaporation as particles leaving a liquid into the air).
• AC9S5I01: pose investigable questions, test relationships, and make reasoned predictions (link expected changes to evaporation).
• AC9S5I02: plan and conduct repeatable investigations, including fair-test variables, safe equipment use, and risk awareness.
• AC9S5I03: use equipment to observe, measure and record data with reasonable precision (planning measurements such as mass, volume, or water level).
• AC9S5I05: compare methods and findings with others; recognise possible sources of error and draw reasoned conclusions (students plan how they will check fairness and accuracy).

Lesson structure (80 minutes)

1. 0–8 min · Starter: “What controls evaporation?” Teacher prompts with a short scenario: “Your school has a small water tank and it disappears faster than expected.” Students do a quick think-pair-share: list factors that might affect evaporation (sunlight, wind/airflow, temperature, surface area, covering).

2. 8–18 min · Direct teach: particle model for evaporation Teacher draws a simple particle model: liquid particles in a container; some escape into surrounding air as they move faster. Students role-play in pairs for 30–40 seconds (as “liquid” particles moving and “gas” particles leaving), then answer: “How does a change in airflow or covering affect particles leaving?”

3. 18–30 min · Project brief: choose your investigation focus Teacher gives the project task: “Design a feasible way to reduce evaporation from a local water source. You will plan a test using fair variables.” Students select one approach category to investigate (e.g., covering, shading, airflow reduction, reducing exposed surface area, using a lid or barrier that still allows access if needed). They record: target site/problem + approach idea.

4. 30–42 min · Build the fair test plan (variables + measurements) Teacher models a planning checklist:

• Variable to change (one factor)
• Variable to measure (water loss indicator)
• Variables to control (container size, starting water amount, time, location conditions as far as possible, measurement method) Students complete a “Fair Test Grid” in notebooks: one change, one measure, 3–5 controls, and a planned measurement method (e.g., mass using a balance, water level using a marked container, or volume using measuring marks).

5. 42–55 min · Engineering challenges discussion (feasibility + constraints) Teacher leads guided discussion using prompts: “What materials will work? What about safety? Will it block access? Will it be easy to maintain? Is it reusable?” Students write a short paragraph: the engineering challenge(s) they expect and how their design addresses them (examples: secure covering, preventing debris contamination, weatherproofing, safe handling of materials, cost and availability).

6. 55–68 min · Method write-up: repeatable and safe Teacher reminds students: investigations must be repeatable by someone else and include risk awareness and safe equipment use. Students draft a step-by-step method with: setup, timing, measurement frequency, and recording table headings. They also list potential risks (sharp edges, spills, trip hazards, use of equipment) and safety actions.

7. 68–75 min · Quick compare + refine (peer check) Teacher has groups exchange their “Fair Test Grid” for a 2-minute check: “Is it fair? What’s the measured outcome? Are controls clear?” Students make one improvement based on feedback.

8. 75–80 min · Exit ticket: reasoned prediction + next step Students answer: “My prediction is… because…” and “Next lesson, I will test by measuring…”

Resources

• Student science project planning sheet (Fair Test Grid + method template)
• Notebook and pens/pencils
• Marker pens and a ruler for measurement planning
• Sample containers (cups/beakers) with measuring marks or sticky labels (for setup planning)
• Balance or measuring tools for planning discussion (if available in room)
• Safety checklist cards (general classroom safety prompts)
• Particle model diagram cards (liquid particles + gas escape arrows)

Assessment

• Formative checks during the “Fair Test Grid” (teacher listens for correct identification of change/measure/control).
• Review students’ engineering paragraph for feasibility and clear reasoning.
• Exit ticket to confirm reasoned prediction and the planned measurement approach.

Differentiation

• Support: provide sentence starters for WALT (“I predict that… because…”, “I will measure… by…”, “I will control…”), and a partially completed Fair Test Grid for students needing structure.
• Support: offer a small set of pre-approved approach categories (cover, shade, reduce airflow, reduce surface area) with example materials.
• Extension scaffold for confident learners: require justification of controls (why each control matters for fairness) and a risk mitigation step for each hazard.
• EAL/SEN: allow diagrams to explain predictions and methods; pair students strategically for the particle role-play and peer check.
• Teacher modelling: use one exemplar method (teacher-created) and highlight where repeatability and safety are included.

Extension (optional for advanced learners)

• Students propose two additional potential solutions and justify which is likely to work best and why, using particle ideas and fairness reasoning (e.g., “Solution A reduces particle escape by covering; Solution B reduces surface area; both may change sunlight impact so controls must be planned.”).