AQA · GCSE · Chemistry
Course version: 8462 · Version from Sept 2018
Students should be able to recognise polymers from diagrams showing their…
Full specification wording
Polymers: Students should be able to recognise polymers from diagrams showing their bonding and structure.
A diagram of a polymer shows a large molecule built from repeating units.
Checked against the AQA 8462 specification (opens in a new tab) on .
- Point 4 of 4
- 3 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
A diagram of a polymer shows a large molecule built from repeating units. The key feature is a continuous chain of covalently bonded atoms, often carbon atoms, with side groups or hydrogen atoms attached. The repeating unit is the part of the chain that repeats many times. To recognise a polymer, look for a long chain rather than a small discrete molecule, and identify the repeating unit by finding the shortest section that repeats along the chain. For example, in poly(ethene) the repeating unit is a two-carbon section with hydrogen atoms attached. The diagram may also show intermolecular forces between neighbouring chains as dashed lines. Recognising these features allows you to distinguish a polymer from a simple molecule such as ethene or from a giant covalent structure such as diamond.
What earns the marks
- A polymer diagram shows a large molecule made from repeating units.
- The atoms in the chain are joined by covalent bonds.
- The repeating unit is the smallest part of the chain that repeats.
- Side groups or hydrogen atoms may be attached to the main chain.
- Dashed lines between chains represent intermolecular forces, not covalent bonds.
Common mistakes and how to put them right
Mistaking a small molecule such as ethene for a polymer.
Put it right by checking whether the diagram shows a long chain with repeating units.
Treating dashed lines between chains as covalent bonds.
Put it right by identifying them as intermolecular forces.
Choosing a repeating unit that does not repeat along the chain.
Put it right by selecting the shortest section that repeats.
Exam tips
- Trace the continuous line of covalent bonds to identify the main chain before looking at side groups.
- Count the atoms in the repeating unit and check that the same pattern repeats along the chain.
- If dashed lines are shown between chains, label them as intermolecular forces rather than bonds.
Try the lesson
The start of the Polymers: Students should be able to recognise polymers from diagrams showing their bonding and structure. lesson, made from checked teaching notes for this specification point.
Have a go first
A substance is represented by the structural diagram shown below.
H H | | -( C - C )- | | n H H
What type of substance does this diagram represent?
Listen
A diagram of a polymer shows a large molecule built from repeating units. The key feature is a continuous chain of covalently bonded atoms, often carbon atoms, with side groups or hydrogen atoms attached. The repeating unit is the part of the chain that repeats many times. To recognise a polymer, look for a long chain rather than a small discrete molecule, and identify the repeating unit by finding the shortest section that repeats along the chain. For example, in poly(ethene) the repeating unit is a two-carbon section with hydrogen atoms attached. The diagram may also show intermolecular forces between neighbouring chains as dashed lines. Recognising these features allows you to distinguish a polymer from a simple molecule such as ethene or from a giant covalent structure such as diamond. A strong answer earns marks for these points. A polymer diagram shows a large molecule made from repeating units. The atoms in the chain are joined by covalent bonds. The repeating unit is the smallest part of the chain that repeats. Side groups or hydrogen atoms may be attached to the main chain. A common slip: Mistaking a small molecule such as ethene for a polymer. Instead, checking whether the diagram shows a long chain with repeating units. Exam tip: Trace the continuous line of covalent bonds to identify the main chain before looking at side groups.
See it
Key words
Say what each word means before you turn the card.
Polymers
Try answering aloud or in your head before turning the card.
Repeating units
Try answering aloud or in your head before turning the card.
Structure recognition
Try answering aloud or in your head before turning the card.
See every definition
- Polymers
- A large molecule built from repeating units, shown in a diagram as a continuous chain of covalently bonded atoms.
- Repeating units
- The smallest part of the chain that repeats many times along the chain.
- Structure recognition
- Looking for a long chain rather than a small discrete molecule, and finding the shortest section that repeats along the chain.
Label the diagram
Some boxes have lost their names. Pick the right name for each number.
1Box 1
2Box 2
3Box 3
There is more to this lesson
The full lesson goes on to check your understanding and help you earn the marks. Create a free account to carry on, with your progress saved.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge
Test your understanding of Polymers: Students should be able to recognise polymers from diagrams showing their bonding and structure.
Active recall beats re-reading. Take an instant quiz now to test what you’ve learned and lock it into long-term memory.
A week of Premium from your first lesson · Then the free plan continues · No card, no charge