Six-mark questions
Six-mark questions are extended open response questions. These require longer answers than the structured questions that have 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
Writing six-mark answers with Dr Alex Lathbridge
Listen to the full series on BBC Sounds.
How to write six-mark answers in your science GCSE exams.
Six-mark 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.
Six-mark 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 six marks, but you do need to write in sentences, linking them logically and clearly.
These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.
Sample question 1 - Foundation
Question
Describe how aluminium is obtained from aluminium oxide on a large scale.
In your answer, refer to the apparatus shown in Figure 1.
Explain why the anode must be replaced regularly. [6 marks]
Figure 1
- Mix together aluminium oxide and cryolite and melt the mixture [1]
- Place in an electrolysis cell with a graphite anode/positive electrode and a graphite cathode/negative electrode [1]
- Pass an electric current through the mixture [1]
- Remove aluminium from the cathode/negative electrode as a liquid [1]
- Oxygen is produced at the anode/positive electrode [1]
- Oxygen reacts with the graphite anode to make carbon dioxide, so the anode burns away and must be regularly replaced [1]
Sample question 2 - Foundation
Question
Describe a safe method for making pure crystals of copper sulfate from copper carbonate and dilute sulfuric acid.
In your method you should name all the apparatus you will use. [6 marks]
Your answer can include any of the following:
- Place sulfuric acid in a beaker.
- Add copper carbonate one spatula at a time
- Until copper carbonate is in excess or until no more effervescence occurs.
- Filter with filter paper and funnel.
- Filter excess copper carbonate.
- Pour solution into evaporating dish/basin.
- Heat using Bunsen burner.
- Pour solution into an evaporating basin and heat over a water bath.
- Stop heating when crystals start to form.
- Allow water to evaporate until pure crystals remain.
- Dry crystals using absorbent paper/warm oven.
- Wear eye protection.
Sample question 3 - Higher
Question
Part of the reactivity series is shown in figure 1.
Figure 1
- Calcium
- Magnesium
- Zinc
- Iron
- Copper
Compare how the different metals shown in figure 1 react with dilute hydrochloric acid. [6 marks]
Your answer can include any of the following:
- Calcium, magnesium, zinc and iron react with dilute hydrochloric acid.
- The products are hydrogen gas...
- ...and a chloride salt.
- The reactions get less vigorous from top to bottom of the reactivity series.
- Calcium reacts very vigorously....
- ...and copper does not react at all.
- The greater the reactivity of the metal, the greater its tendency to form positive ions.
- Calcium has a high tendency to lose electrons/form positive ions.
- Copper has a low tendency to lose electrons/form positive ions.
Sample question 4 - Higher
Question
Electrolysis of acidified water can produce hydrogen and oxygen.
The apparatus for the electrolysis is:
- water containing some dilute sulfuric acid
- two graphite rods
- a suitable container for the electrolysis reaction
- a suitable source of electricity
- test tubes
Describe how to use the apparatus to electrolyse acidified water, and how to test the gases to show that they are hydrogen and oxygen.
Include a diagram in your answer. [6 marks]
Your answer can include any of the following:
Experiment set up:
- acidified water in container (eg beaker)
- graphite rods in acid
- attach rods to electrical supply
- DC supply
- test tubes to collect gases
Test for hydrogen:
- lighted splint
- squeaky pop
Test for oxygen:
- glowing splint
- relights
Note: No diagram is shown in this sample answer. However, if instructed, one should be given in exam conditions.
