Long-chained molecules formed by joining together monomers.

A pulling force that keeps particles close together.

A product that is manufactured from natural resources.

A substance that is added to a polymer to increase its flexibility.

A chemical bond between different chains of atoms in a polymer.

Structure of polymers

Science

Materials and composites: including metals, ceramics and polymers

The reactivity series for metals

Chemical reactions: displacement of metals

Catalysts

In the Using Earth's Resources unit, pupils will build on their knowledge of materials to explore the extraction and purification of metals, life cycle assessments, and recycling.

In the Acids and Bases unit, pupils learned about the properties of acids, bases, alkalis, and the neutralisation reaction.

This unit examines the varying properties of elements, the reactivity series, and the role of carbon in metal extraction. It also explores catalysts and the properties of ceramics, polymers, and composites. Emphasis is placed on evaluating risks, using appropriate techniques, and interpreting data.

Materials

a strong force that holds atoms together in a compound

a chemical bond between atoms in different polymer chains

a pulling force that keeps particles close together

a substance that is added to a polymer to increase its flexibility

Match the following key terms to their definition.

Materials can be natural or synthetic. Natural means they occur in nature. Synthetic means they are {{}}.

branched polymer; polymer with plasticiser; cross–linked polymer

branched polymer; cross–linked polymer; polymer with plasticiser

cross–linked polymer; polymer with plasticiser; branched polymer

cross–linked polymer; branched polymer; polymer with plasticiser

polymer with plasticiser; cross–linked polymer; branched polymer

Polymers can be represented with models. Which list correctly describes the image with three polymer models, from left to right?

natural; carbohydrate found in plant cell walls

natural; nucleic acid involved in carrying genetic information

synthetic; high density poly(ethene) used for plastic bottles

synthetic; low density poly(ethene) used for plastic bags

synthetic; poly(vinyl chloride) used for sockets, switches and wellies

natural; protein fibre often made by sheep

Match the following key terms to their description.

Cross–links in polymers make it harder for polymer molecules to slide past each other. {{}} in between polymer chains push the long molecules apart so that forces of attraction are weakened.

In polymers, forces of attraction are the same as chemical bonds.

In polymers, forces of attraction are weaker than cross–links.

In polymers, forces of attraction are weakened by plasticisers.

In polymers, forces of attraction are weakened by branches.

A chemical bond is a strong force that holds atoms together in a compound. A chemical bond takes a lot of energy to overcome and break.
Which of the following statements are correct?

Which of the following three properties make polymers useful for making plastic water bottles?

Plastics are polymers, but not all polymers are plastics. Which of the following materials are classified as polymers?

Models are used in science to test ideas without facing practical or ethical issues. However, they have {{}}, such as only representing one aspect of a concept rather than the whole.

a substance where two or more different elements are chemically bonded

a substance made up of only one type of atom

made up of two or more atoms chemically bonded (usually non–metals)

Which of the following properties of rubber makes it useful for making rubber bands?

the atoms move around each other in the water molecules

the chemical bonds in the water molecules become weaker

the water molecules have enough energy to overcome the forces between them

the water molecules move around each other more in the liquid

Consider ice, water, and water vapour. The atoms and molecules are held together differently and with varying strengths. What happens at the boiling point when water turns to water vapour?

Structure of polymers

Lesson outcome