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.
Sample question 1 - Foundation
Question
You are provided with four solids which are soluble in water. Some of them dissolve during an exothermic reaction, and some dissolve during an endothermic reaction. Describe how you would identify which dissolving process absorbs and releases the most energy.
Your description should include a list of apparatus or a labelled diagram, how you will make the investigation a fair test, and how you would interpret the results.
[6 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
Apparatus:
- Polystyrene cup or (glass) beaker
- Thermometer
- Top pan balance
- Measuring cylinder
Method (including fair testing):
- Measure the same volume of water into the cup
- Measure the same mass of solid
- Record the temperature of the water
- Add the solid and stir until dissolved
- Record the maximum or minimum temperature
Interpretation of results:
- Calculate the temperature difference for each solute
- Temperature increases mean exothermic reactions/temperature decreases mean endothermic reactions
- Largest temperature changes mean the most exothermic or endothermic reactions
Sample question 2 - Foundation
Question
Cars can be purchased in the UK which are powered by rechargeable lithium ion cells. These cars can be recharged from mains electricity. When fully charged, the car can drive approximately 150 miles before needing to be recharged.
Cars are being developed that are powered by hydrogen fuel cells. These cars use oxygen from the air and react it with hydrogen which is stored in tanks in the car as a compressed liquefied gas. The car can drive approximately 300 miles on a full tank of hydrogen.
Evaluate the use of hydrogen fuel cells and rechargeable cells to power environmentally friendly cars in the future.
[6 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
Rechargeable cells – advantages
- Can be recharged easily at home and at work
- Easy to install charging points at service stations and petrol stations
- Produces no pollution when driving
Rechargeable cells – disadvantages
- Low range – will need frequent recharging/not suitable for long journeys
- Electricity for recharging may have been generated by burning fossil fuels, so still contributes to global warming
Hydrogen fuel cells – advantages
- Produces no pollution when driving
- Longer range – suitable for long journeys
- Hydrogen can be produced from water via electrolysis
Hydrogen fuel cells – disadvantages
- Hydrogen is a flammable gas, so potentially dangerous to store and refuel
- Hydrogen may have been generated from water using electricity which was generated by burning fossil fuels, so still contributes to global warming
Conclusion - any conclusion is acceptable, as long as it is justified using the above points.
Sample question 3 - Higher
Question
A student is given four different powdered metals and some dilute sulfuric acid. The student wants to investigate the reactivity of the four metals.
Outline a plan that the student could use to investigate the relative reactivity of the metals. The plan should use the fact that all four metals react exothermically with dilute sulfuric acid. You should name the apparatus used and comment on the safe use of the chemicals.
[6 marks]
This question is AQA material which is reproduced by permission of AQA.
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
Apparatus:
- Thermometer
- Measuring cylinder
- Stirring rod
- Spatula
- Plastic cup (with lid) or beaker
- Stopwatch
- Filter paper or watch glass
- Balance
Method:
- Weigh the same mass of each metal in each same state of division, eg powder
- Measure a set volume of sulfuric acid into a plastic cup or beaker
- Measure and record the temperature of the sulfuric acid
- Add metal W into the plastic cup or beaker
- Stir and record the highest temperature or record the temperature after a set time
- Calculate the increase in temperature
- Repeat the method for metals X, Y and Z
- Repeat for each metal at least three times to calculate a mean
Safe use:
- Comment on safe use should include wearing safety glasses
Sample question 4 - Higher
Question
The diagram below shows the reaction between ethene and chlorine and is similar to the reaction between ethene and bromine.
"The more energy levels (shells) of electrons an atom has, the weaker the covalent bonds that it forms."
Use the above statement to predict and explain how the overall energy change for the reaction of ethene with chlorine will differ from the overall energy change for the reaction of ethene with bromine.
[6 marks]
This question is AQA material which is reproduced by permission of AQA.
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
Size and strength:
- Chlorine atoms have fewer electron energy levels/shells
- Chlorine atoms form stronger bonds
- Cl−Cl bond stronger than Br−Br
- C−Cl bond stronger than C−Br
Energies required:
- More energy required to break bonds with chlorine
- More energy given out when making bonds with chlorine
- Overall energy change depends on sizes of energy changes
Conclusions:
- If C−Cl bond changes more, then less exothermic
- If C−Cl bond changes more, then more exothermic
- We can't tell how overall energy change will differ as we do not know which changes more
