Lesson overview

In this chemistry Key Stage 3 (KS3) lesson, students investigate the different properties of plastics. In groups students design an investigation testing either thermal insulation or tensile strength. Included are teacher resources with an investigation template.

Learning outcomes

• Describe how plastics can be both harmful and useful
• Identify independent, dependent, and control variables
• Develop investigation skills including control variables and repeats
• Evaluate results in a graph
  

Lesson steps

1. I couldn’t disagree more because... (5 mins)
   Students use media-based knowledge on plastics to describe how they can be both harmful and useful. These ideas are put on the board. Students work in pairs to play ‘I couldn’t disagree more because’.
   
2. Variables (5 mins)
   Teacher explains what independent, dependent, and control variables are. The teacher shows two examples of investigations into plastics with the variables identified.
   
3. Designing a practical (35 mins)
   Students design and carry out their own investigation using Student Sheet 2a: Plastics independent investigations.
   
4. Analyse Data (10 mins)
   Students must graph their data using the design your test worksheet.
   
5. Reflection: love, recycle, bin (5 mins)
   Students reflect on the lesson. They state one thing they loved, one thing they would bin (had rather not done) and one thing learned that they would like to recycle (needed for the next lesson).

England

Science Key Stage 3

Materials

• Properties of polymers

Energy changes

• Heating and thermal equilibrium: how a temperature difference between two objects leads to energy transfer from the hotter to the cooler one, through contact (conduction) or radiation, and how such transfers tend to reduce the temperature difference. Use of insulators.

Scientific working skills

• Make predictions using scientific knowledge and understanding.
• To select, plan and carry out the most appropriate types of scientific enquiries to test predictions, including identifying independent, dependent and control variables, where appropriate.
• To use appropriate techniques, apparatus, and materials during fieldwork and laboratory work, paying attention to health and safety.
• To make and record observations and measurements using a range of methods for different investigations; and evaluate the reliability of methods and suggest possible improvements.