| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Chemistry |
| Lesson Topic: State that water from natural sources may contain substances, including: (a) dissolved oxygen (b) metal compounds (c) plastics (d) sewage (e) harmful microbes (f) nitrates from fertilisers (g) phosphates from fertilisers and detergents |
Learning Objective/s:
- Describe the range of substances commonly found in natural water sources.
- Explain the environmental and health impacts of each listed substance.
- Identify appropriate laboratory or field tests for detecting these substances.
- Evaluate how contamination levels influence water‑quality assessments.
|
Materials Needed:
- Projector and screen
- Whiteboard and markers
- Handouts summarising substances and test methods
- DO meter or Winkler titration kit (demonstration)
- Colourimetric test kits for metals, nitrates, and phosphates
- Sample water containers for the demo
- Laptop with presentation slides
|
Introduction:
Begin with a striking image of a polluted river to capture students' attention. Ask learners what they think determines whether water is safe to drink, linking to prior knowledge of clean‑water concepts. Explain that by the end of the lesson they will be able to list common contaminants, describe their impacts, and choose appropriate detection methods.
|
Lesson Structure:
- Do‑now (5'): Students list substances they think might be in a natural lake and share responses.
- Mini‑lecture (10'): Present the seven key contaminants with a slide and diagram, highlighting sources and impacts.
- Interactive activity (12'): In groups, match each contaminant to its typical source and health effect using card sets.
- Demonstration (10'): Show a DO meter and a colourimetric nitrate test on a water sample; discuss result interpretation.
- Quick check (8'): Whole‑class Kahoot quiz on detection methods for each contaminant.
- Reflection (5'): Exit‑ticket where students note one surprising contaminant and one test they could use.
|
Conclusion:
Summarise that natural waters invariably contain a variety of chemical and biological substances, each with specific origins and risks. Reinforce that accurate testing is essential for water‑quality management. For homework, assign a short research task where students find a recent news article about water contamination and identify the pollutant and the test used to detect it.
|