Understanding how to approach exam questions helps to boost exam performance. Question types will include multiple choice, structured, mathematical and practical questions.

Remember that you will need to take a ruler and calculator into the exam.

Questions that test mathematical skills will often start with the command words like 'Calculate...' 'Determine...', 'Estimate...' and 'Measure...'. They will then include blank space for you to show your working.

When an answer to a maths question is marked:

- full marks are given for the right answer (but it is very important to show your working, so you can check your answer and so that, if you make a small slip, you can still get marks for your working)
- marks are given for working, including substitution and rearrangement,
- if you make a small mistake, the examiner will give you credit for your 'error carried forward'.

An 'error carried forward' means that, in questions with more than one part, your answer to a later question part will be marked according to your answer for the earlier part, even if you got this wrong. So, you could still get full marks in the later answer if your working is correct but you use the incorrect earlier answer.

If your answer has many decimal places or figures, make sure you give it to an appropriate number of decimal places or significant figures. If in doubt, match the number of decimal places or significant figures to the data given in the question.

You may be asked to give units. This may earn you an additional mark, so don’t forget to check whether you need to do this.

Maths questions might ask you to plot or complete a graph or table. When you draw a graph, make sure you:

- plot each point accurately
- draw a best fit straight line or curve

You may be given a grid with axes labelled and scales already given. Sometimes you may be given an empty grid for you to supply your own axes. When you do this:

- put the independent variable (the one that is being changed in the experiment) on the x-axis and the dependent variable (the one that changes as a result) on the y-axis
- make sensible scales so that the plotted points cover at least half of the area of the graph
- label the axes with their quantity and unit, eg time (s)

*Questions courtesy of Eduqas.*

- Question
Potassium reacts vigorously with water forming potassium hydroxide and hydrogen gas, H

_{2}.Complete and balance the symbol equation for this reaction.

2K + 2H

_{2}O → _______ + _______**[2 marks]***Question courtesy of Eduqas.*2K + 2H

_{2}O → 2KOH + H_{2}[2]The formula and balanced equation each gain one mark.

- Question
The table below shows some properties of the elements in group 0 - the noble gases.

Element Atomic mass Melting point Boiling point Helium 4 -272°C -269°C Neon 20 -249°C -246°C Argon 40 -186°C Krypton 84 -157°C -152°C Xenon 112 -112°C -105°C Use the data in the table to estimate the melting point of argon.

**[1 mark]***Question courtesy of Eduqas.*A value between -249 and -187°C [1]

- Question
Write the balanced symbol equation for the reaction that takes place between bromine and sodium iodide.

**[2 marks]***Question courtesy of Eduqas.*Br

_{2}+ 2NaI → 2NaBr + I_{2}[2]The formula and balanced equation each gain one mark.

- Question
A bar chart of the densities at room temperature of all the elements in group 0 of the periodic table is shown below.

Give the trend in the densities of the noble gases going down this group.

**[2 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 density increases from helium to radon [1]
- the difference in densities increases on going down the group, so the change in density gets larger [1]