Open response questions

Extended open response questions require longer answers than structured questions that have fewer marks. Open response questions are usually worth six marks, but some are worth fewer marks. It is wise to plan your answer first by making some notes. This will help you to include all the key points.

To gain full marks, you need to:

  • support explanations using scientific knowledge and understanding
  • use appropriate scientific words
  • write clearly and link ideas in a logical way
  • maintain a sustained line of reasoning

Open response questions often use these command words:

  • Describe means you should recall facts, events or processes accurately. You might need to give an account of what something looked like, or what happened.
  • Explain means you need to make something clear, or state the reasons for something happening.
  • Compare means you need to describe similarities and differences between things. If you are asked to compare X and Y, write down something about X and something about Y and give a comparison. Do not just write about X only or Y only.
  • Evaluate means you must use information supplied, or your own knowledge, to consider the evidence for and against or to identify strengths and weaknesses. You must then complete your answer with a conclusion, stating which is better and why, for example.

Open response questions may be synoptic questions, which bring together ideas from two or more topics. For example, a question about fertilisers could include ideas about covalent substances, acids and alkalis, chemical calculations and effects on the environment.

The answers shown here give marking points as bullet points. You do not usually need to include all of them to gain full marks, but you do need to write in sentences, linking them logically and clearly.

This page contains AQA material which is reproduced by permission of AQA.

Sample question 1 - Foundation


Some students want to build an electromagnet.

The students have the equipment shown in below.

Equipment needed for the practical; insulated wire, iron nail, power supply, connecting leads, steel paperclips and a wooden clamp and stand

Describe how the students could build an electromagnet. Include in your answer how the students should vary and test the strength of their electromagnet. [6 marks]

Indicative content

Details of how to make an electromagnet:

  • wrap the wire around the nail
  • connect the wire to the power supply
  • switch on the power supply

Details of how to vary the strength of the electromagnet:

  • change the number of turns (on the coil)
  • change the current (through the coil)
  • change the separation of the turns

Details of how to test the electromagnet:

  • suspend paperclips from the electromagnet
  • the more paperclips suspended, the stronger the electromagnet is
  • clamp the electromagnet at different distances from the paperclip
  • the further the distance from which paperclips can be attracted the stronger the electromagnet is
  • test before and after making alterations to change the strength
  • compare the results from before and after making the alterations
  • use de-magnetised paper clips

Sample question 2 - Foundation


Electromagnets are used in scrapyards to lift cars.

An electromagnet is a solenoid.

Explain why it is better to use an electromagnet rather than a permanent magnet in a scrapyard.

You should include a comparison of the properties of electromagnets and permanent magnets in your answer. [4 marks]

Indicative content

  • An electromagnet can be switched on and off.
  • So it can be used to lift a car body.
  • And release a car body.
  • It can easily be used to move car bodies from one place to another in the scrapyard.
  • A permanent magnet cannot be switched off to release a car body.
  • So would not be as useful in the scrapyard.
  • The strength of the magnetic field of an electromagnet can be varied.
  • So an electromagnet can lift different masses.
  • So can deal with different vehicles.
  • But the strength of the magnetic field of a permanent magnet cannot be varied or is fixed.
  • So a permanent magnet can only lift up certain masses.

Sample question 3 - Higher


Explain why chlorine (Cl2) is a gas at room temperature, but sodium chloride (NaCl) is a solid at room temperature.

An illustration of chlorine as a gas and sodium chloride as a solid

Include a description of the bonding and structure of chlorine and sodium chloride in your answer. [6 marks]

Indicative content


  • covalent bonds between atoms
  • forming (simple) molecules
  • no / weak attraction / bonds between molecules
  • low boiling point

Sodium chloride:

  • ionic bonds or electrostatic attraction
  • strong bonds
  • in all directions
  • between oppositely charged ions
  • forming giant lattice
  • large amount of energy needed to break bonds
  • high melting point