Particles - Maths questions
Don鈥檛 forget to take a ruler and calculator into the exam.
Maths questions 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鈥檚 wise to show your working so you can check your answer).
- Marks are given for working, including substitution and rearrangement.
- Errors carried forward are taken into account.
If a later answer depends on an earlier answer, and you get the earlier one wrong, you could still get full marks in the later answer if your working is correct.
If your answer has many decimal places or figures, make sure you give it to an appropriate number of decimal places or significant figures. You may be asked to give units. This may earn you an additional mark, so don鈥檛 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 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 on the x-axis and the dependent variable on the y-axis
- make sensible scales so that the plotted points cover at least 50% of the area of the graph
- label the axes with their quantity and unit, eg time (s)
Learn maths skills with Dr Alex Lathbridge
Listen to the full series on 大象传媒 Sounds.
Sample question 1 - Foundation
Question
The symbol for a phosphorus atom is \(_{15}^{31}\)P.
Calculate the numbers of protons, neutrons and electrons this atom contains.
[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.
- protons = 15 and electrons = 15 [1]
- neutrons = (31 - 15) = 16 [1]
Sample question 2 - Foundation
Question
Look at the table. It shows information about some atoms.
Atom | Atomic number | Mass number | Number of protons | Number of neutrons | Number of electrons |
A | 8 | 16 | ................. | 8 | ................. |
B | ................. | ................. | 11 | 12 | 11 |
C | ................. | 27 | 13 | ................. | 13 |
Atom | A |
---|---|
Atomic number | 8 |
Mass number | 16 |
Number of protons | ................. |
Number of neutrons | 8 |
Number of electrons | ................. |
Atom | B |
---|---|
Atomic number | ................. |
Mass number | ................. |
Number of protons | 11 |
Number of neutrons | 12 |
Number of electrons | 11 |
Atom | C |
---|---|
Atomic number | ................. |
Mass number | 27 |
Number of protons | 13 |
Number of neutrons | ................. |
Number of electrons | 13 |
Complete the table.
[3 marks]
OCR Gateway Science, GCE Chemistry, Paper J248, 2016.
Atom | Atomic number | Mass number | Number of protons | Number of neutrons | Number of electrons |
A | 8 | 16 | 8 | 8 | 8 |
B | 11 | 23 | 11 | 12 | 11 |
C | 13 | 27 | 13 | 14 | 13 |
Atom | A |
---|---|
Atomic number | 8 |
Mass number | 16 |
Number of protons | 8 |
Number of neutrons | 8 |
Number of electrons | 8 |
Atom | B |
---|---|
Atomic number | 11 |
Mass number | 23 |
Number of protons | 11 |
Number of neutrons | 12 |
Number of electrons | 11 |
Atom | C |
---|---|
Atomic number | 13 |
Mass number | 27 |
Number of protons | 13 |
Number of neutrons | 14 |
Number of electrons | 13 |
Sample question 3 - Higher
Question
The symbol for a potassium ion is \(_{19}^{39}\)K+
Calculate the numbers of protons, neutrons and electrons this ion contains.
[3 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.
- protons = 19 [1]
- neutrons = (39 - 19) = 20 [1]
- electrons = (19 - 1) = 18 [1]
Sample question 4 - Higher
Question
The symbol for an oxide ion is \(_{8}^{16}\)O2-
Calculate the numbers of protons, neutrons and electrons this ion contains.
[3 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.
- protons = 8 [1]
- neutrons = (16 - 8) = 8 [1]
- electrons = (8 + 2) = 10 [1]