Life Cycles | Project Based Learning
Students investigate how matter changes through natural and human-made life cycles by analyzing and comparing the life cycle of a product or material (e.g., water bottle, cell phone, paper, fertilizer, or concrete). In teams, they research the chemistry behind production, use, breakdown, reuse, and disposal, then create a lifecycle model or presentation showing chemical processes, environmental impacts, and opportunities for sustainable design.
| Term | Definition |
|---|---|
| Life cycle | The stages a product or material goes through from extraction or production to use, disposal, reuse, or recycling. |
| Raw material | A natural resource used to make a product. |
| Chemical change | A change that forms one or more new substances with different properties. |
| Physical change | A change in form or state without creating a new substance. |
| Decomposition | The breakdown of substances into simpler substances, often by natural processes or microorganisms. |
| Recycling | Processing used materials to make new products. |
| Sustainability | Using resources in ways that reduce harm and support long-term environmental health. |
| Conservation of mass | The principle that matter is not created or destroyed in a closed system during a chemical reaction. |
Show a common product and ask: 'What chemistry is hidden in its life cycle?' Present the driving question and explain the final project: teams will map the product’s chemical life cycle and propose one improvement for sustainability.
Observe the product, generate initial ideas, and record questions about how it is made, used, and disposed of.
Review key concepts: raw materials, physical vs. chemical change, decomposition, recycling, and environmental impact. Model a simple life cycle using aluminum cans or paper.
Take notes, ask clarifying questions, and identify one chemical process in the model example.
Provide a list of approved products/materials or allow teams to choose one with teacher approval. Assign or confirm teams and distribute project organizers.
Form teams, choose a topic, and define the product or material they will investigate.
Circulate, conference with teams, and prompt deeper thinking with questions such as: 'What chemical reactions occur here?' 'Where does energy enter or leave the system?' 'What happens at end-of-life?'
Research the full life cycle, collect evidence, identify chemical processes at each stage, and note environmental impacts and possible improvements.
Support teams in organizing information into a lifecycle model, poster, slide deck, or digital infographic. Require labels for stages, chemical processes, and sustainability notes.
Create the visual product, write concise scientific explanations, and prepare to present findings.
Facilitate a quick gallery walk or structured peer feedback using two prompts: one strength and one question/suggestion.
Review another team’s work, give feedback, and revise their own project based on comments.
Invite brief team presentations or a few spotlight shares. Connect student examples back to the driving question and class concepts.
Present key findings, explain the chemistry in their life cycle, and compare one sustainability improvement across products.
Revisit the driving question and have students name one chemistry concept that changed their thinking about the product’s life cycle. Summarize that chemistry helps explain not only how materials are made and used, but also how they can be redesigned for lower impact and longer-term sustainability.