What the lesson is about
My senior students have switched off, so I tell them we are going to produce two contracts, one for me and one for them, writes Sarah Longshaw. I aim to produce variety in lessons and homework tasks, and they want rewards. They agree to cooperate, do homework and to believe "I can". We sign our contracts.
I have to deliver variety now. We start by making Molymod models of alkenes and then connect them to make polymers. We summarise our findings with brief sentences and drawings. We make paper chains, writing the name of a monomer (propene) on each link and then joining them together to form polypropene. We practise naming polymers given the monomer and vice-versa; we draw the structural formulae.
Taking it further
The lesson moves towards disposal of plastics. "Why not burn them?" So we do. As the smoke clears, we discuss combustion and compare complete and incomplete combustion. We write the word "equations". We decide plastics can be recycled and, with a bag of plastic "rubbish", we examine the codes that tell us the different types. We fill in a worksheet from TES Resources that requires students to look up answers to nine questions from the topic and put them on the grid. Anyone who finishes gets a raffle ticket. They look in the textbook, remembering how to use the index, cooperate and complete the activity.
For a fun, musical way to revise variables, try baibel's Variables Song. Or activate the investigator in every pupil with mad.scientist's hovering paperclip challenge. Jacqui1974 shares a fun "slime-making" activity for a polymers practical.