Six-mark questions

Six-mark questions are extended open response questions. These require longer answers than the structured questions. It is wise to plan your answer rather than rushing straight into it, otherwise you may stray away from the key points.

Most questions on exam papers have mark schemes that give key points that are given marks. The six-mark questions are marked differently - they use a levels-based mark scheme. This type of mark scheme is used because these questions are more open-ended. To gain full marks, you need to:

  • support explanations using scientific knowledge and understanding
  • use appropriate scientific words and terms
  • write clearly and link ideas in a logical way
  • maintain a sustained line of reasoning, rather than getting lost or bogged down

Six-mark questions often use these command words:

  • describe - you need to give an account but no reason
  • explain - you must give reasons or explanations
  • devise - you must plan or invent a procedure using your scientific knowledge and understanding
  • evaluate - you must review information, including identifying strengths and weaknesses, and make a supported conclusion

Six-mark questions may be synoptic questions. These questions 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 six marks, but you do need to write in full sentences, linking them logically and clearly.

Answers are placed in three marking bands:

  • 1 to 2 marks for answers showing limited content and reasoning and with significant omissions.
  • 3 to 4 marks for answers that give some relevant points, with linking and reasoning and with fewer omissions.
  • 5 to 6 marks for answers that link most of the relevant points, with good links and reasoning. They will have few, if any, omissions.

Questions courtesy of Eduqas.

Sample question 1 - Foundation


Burning fossil fuels such as coal causes acid rain. Describe how acid rain is formed and its effects on the environment. [6 marks]

Your answer should include the following:

  • all rainwater is slightly acidic
  • sulfur is present as an impurity in coal and forms sulfur dioxide gas when it burns
  • S + O2 → SO2
  • sulfur dioxide enters the atmosphere and reacts with/dissolves in rainwater
  • produces significantly acidic solution/sulfuric acid which falls as acid rain
  • acid rain erodes limestone statues and buildings, corrodes metal structures such as bridges
  • acid rain damages plants and vegetation and aquatic life


Sample question 2 - Higher


Explain how natural processes keep the carbon dioxide and oxygen content of the atmosphere approximately constant. Discuss how human activities are changing the balance between these gases. [6 marks]

Your answer should include the following:

  • a description of photosynthesis producing oxygen and removing carbon dioxide
  • a description of respiration removing oxygen and producing carbon dioxide
  • discussing combustion
  • oxygen is reduced to produce carbon dioxide during this process
  • discussing deforestation
  • this reduces the number of plants available to produce oxygen and to reduce the amount of carbon dioxide in the atmosphere
  • increases the percentage of carbon dioxide in the air leading to global warming