1. Produced from plant material using micro-organisms 2. Biodegradable
3. Degrade within months or years
Fig. 17 Compostable bags are made from natural materials and completely break down.
Nature of Science
In this chapter we looked at how different materials are extracted, used and disposed of or recycled. Scientists are developing new technologies for recycling different materials, and machinery has been designed to address the problem of sorting recycled materials. Question: Extraction of the materials that we use can damage the environment. Investigate how scientists have helped to develop more sustainable mining methods.
Chapter Summary
1. Wood, metals and plastics are materials that are commonly used. 2. Obtaining these materials requires a lot of energy, machinery and chemicals. 3. Extraction methods can have a significant impact on the environment. 4. Disposing of materials can cause pollution of air, soil and water. 5. The lifespan of materials differs greatly; newspaper can decompose in six weeks whereas plastic bottles could take up to 450 years to decompose.
6. Recycling reuses materials and reduces the amount of energy needed to make products.
