A Level Official Exam Material
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​​​​​​​Unit 1: Structure, Bonding and Introduction to Organic Chemistry
Topic 2: Atomic Structure and the Periodic Table
For both AS and A Level students
Q1. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
Which statement about subatomic particles is correct? 
A neutral atoms always contain the same number of protons and electrons 
B neutral atoms always contain the same number of protons and neutrons
 C electrons have a relative mass of 1 and a charge of −1 
D protons have a relative mass of 1 and no charge 
(Total for question = 1 mark) 

Q2. This question is about phosphorus and sulfur. 
Which species contains 15 protons, 16 neutrons and 18 electrons? (1) 
A P 3− 
B P 3+ 
C S 2− 
D S 2+ 
(Total for question = 1 mark)
Q2. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
Isotopes are atoms of an element that have different 
A electronic structures 
B numbers of electrons 
C numbers of protons 
D numbers of neutrons 
(Total for question = 1 mark)
Q3. The hydroxide ion, OH– , has a total of 9 protons. 
How many neutrons and electrons are there in this ion?
Q4. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
The diagram shows a mass spectrometer.
(a) Which process occurs in region R? (1) 
A the sample is vaporised using a heater 
B electrons are removed from molecules or atoms and positive ions are formed 
C electrons are added to the molecules or atoms and negative ions are formed 
D ions are accelerated by an electric field 

(b) Which statement is correct for region T? (1) 
A ions with a greater mass have a smaller deflection 
B ions with a greater mass have a greater deflection 
C ions with a greater charge have a smaller deflection 
D ions are speeded up by a magnetic field 
(Total for question = 2 marks)
Q5. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
The mass spectrum of a sample of silicon is shown
What is the best estimate for the relative atomic mass of silicon in this sample? 
A 28.0 
B 28.2 
C 28.8 
D 29.0 
(Total for question = 1 mark)
Q6. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
Iodine exists as one isotope with mass number 127. 
Chlorine exists as two isotopes with mass numbers 35 and 37. 
How many molecular ion peaks are there in the mass spectrum of ICl3? 
A 2 
B 3 
C 4 
D 5 
(Total for question = 1 mark)
Q7. Answer the questions with a cross in the boxes you think are correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
The mass spectrum of a sample of an element is shown.
(a) What is the Ar of the element? (1) 
A 42.0 
B 48.0 
C 63.6 
D 64.0 

(b) Which species could be responsible for the peak at m / z = 32.5? (1) 
A 32S + 
B 63Cu2+ 
C 65Cu2+ 
D 98Tc3+ 
(Total for question = 2 marks)
Q8. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
The mass spectrum of a sample of an element has only two peaks
What is the approximate relative atomic mass of the element in this sample? 
A 191.5 
B 192.0 
C 192.5 
D 193.0 
(Total for question = 1 mark)
Q9. Data from the mass spectrum of a sample of pure iron is given in the table.
Which species is most likely to cause the peak at m/z = 28? (1) 
A 28Fe+ 
B 56Fe2+ 
C 28Si+ 
D 84Sr 
(Total for question = 1 mark)
Q10. This question is about compounds containing chlorine. 
(c) Nitrogen trichloride has the formula NCl3. 
(i) A sample of nitrogen trichloride contained only nitrogen atoms with mass number 14, and chlorine atoms with mass numbers 35 and 37. 
Give the formula and mass/charge ratio for each of the four ions responsible for the molecular ion peaks in the mass spectrum of nitrogen trichloride. (2) 
(Total for question = 2 marks)
Q11. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
Which is the equation for the second ionisation energy of an element, A? 
A A(g) → A 2+(g) + 2e− 
B A + (g) → A 2+(g) + e− 
C A 2+(g) → A 3+(g) + e− 
D A 2+(g) → A 4+(g) + 2e− 
(Total for question = 1 mark)
Q12. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
Which equation represents the third ionisation energy for element J? 
A J 2+(g) → J 3+(g) + e– 
B J 3+(g) → J 4+(g) + e– 
C J(g) → J 3+(g) + e– 
D J(g) → J 3+(g) + 3e–
(Total for question = 1 mark)
Q13. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
Which equation represents the second ionisation energy of magnesium? 
A Mg(g) → Mg2+(g) + 2e− 
B Mg+ (g) → Mg2+(g) + e− 
C Mg(s) → Mg2+(s) + 2e− 
D Mg+ (s) → Mg2+(s) + e− 
Use this space for any rough working. Anything you write in this space will gain no credit. 
(Total for question = 1 mark)
Q14. What is the equation for the third ionisation energy of aluminium? (1) 
A Al(g) → Al3+(g) + 3e− 
B Al(s) → Al3+(s) + 3e− 
C Al2+(g) → Al3+(g) + e− 
D Al2+(s) → Al3+(s) + e− 
(Total for question = 1 mark)
Q15. The decrease in first ionisation energy down Group 1 in the Periodic Table is caused by the increase in (1) 
A force of attraction between the nucleus and outer electron 
B number of neutrons in the nucleus 
C number of protons in the nucleus 
D shielding of the outer electron from the nuclear charge 
(Total for question = 1 mark)
Q16. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
Which is the electronic configuration of the Sc3+ ion? 
A 1s2 2s2 2p6 3s2 3p6 
B 1s2 2s2 2p6 3s2 3p5 3d1 
C 1s2 2s2 2p6 3s2 3p6 3d1 4s 2 
D 1s2 2s2 2p6 3s2 3p6 3d4 4s2 
(Total for question = 1 mark)
Q17. This question is about the chlorides of beryllium and calcium. 
(a) Complete the electronic configurations of the atoms of beryllium and calcium using the s, p, d notation. (2) 
Be 1s2 ............................................................................................................................................. 
Ca 1s2 ............................................................................................................................................. 
(Total for question = 2 marks)
Q18. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
What is the electronic configuration of the nitride ion, N3– ? 
A 1s2 2s2 
B 1s2 2s2 2p3 
C 1s2 2s2 2p4 
D 1s2 2s2 2p6 
(Total for question = 1 mark)
Q19. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
Which ion has the electronic configuration 1s2 2s2 2p6 3s2 3p6 in its ground state? 
A Al3+ 
B Cl− 
C N3− 
D Na+ 
(Total for question = 1 mark)
Q20. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
A p-block element in Period 3 of the Periodic Table reacts to form an ionic compound. 
What could be the electronic configuration of the ion formed by this element? 
A 1s22s22p63s2 
B 1s22s22p63s23p6 
C 1s22s22p63s23p63d10 
D 1s22s22p63s23p63d104s24p6 
(Total for question = 1 mark)
Q21. Which element is in the d-block of the Periodic Table? (1) 
A argon 
B chlorine 
C iron 
D sodium 
(Total for question = 1 mark) 

Q22. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
A stable ion, M3+, contains 18 electrons. 
In which block of the Periodic Table is element M found? 
A s 
B p 
C d 
D f 
(Total for question = 1 mark)
Q23. The graph shows the first ionisation energies for the elements with atomic numbers from 3 to 12.
(a) Write the equation for the first ionisation energy of nitrogen. Include state symbols. (2) 
(b) Explain the changes in first ionisation energy for the elements with atomic numbers from 3 to 10. (4) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. 
(c) Explain why the first ionisation energy of element 11 is lower than that of element 3. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. 
(Total for question = 8 marks)
Q24. Aluminium is an abundant metal with many uses. 
(a) The first four ionisation energies of aluminium are shown.
Explain how this information shows that aluminium is in Group 3 of the Periodic Table. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
(b) The graph shows the first ionisation energies for the elements in Period 3.
(i) Explain the general increase in the first ionisation energy from sodium to argon. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. 
(ii) Explain why the first ionisation energy of aluminium is less than the first ionisation energy of magnesium. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. 
(Total for question = 6 marks)
Q25. This question is about the structure of atoms. 
(a) State what is meant by the term orbital. (2) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................

(b) State the shape of an s orbital and the shape of a p orbital. (1) ............................................................................................................................................. ............................................................................................................................................. 
(c) Describe what can be deduced about the electronic structure of sodium from its successive ionisation energies. (3) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
Q26. This question is about the element sulfur.
(a) Complete the diagram to show the electronic configuration for a sulfur atom in the ground state. Include labels for each subshell.
(b) Write an equation for the first ionisation energy of sulfur. Include state symbols. (2) (c) Explain why the first ionisation energy of sulfur is less than the first ionisation energies of both phosphorus and chlorine. (3) ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................. .............................................................................................................................................
Q27. Answer the question with a cross in the box you think is correct . 
If you change your mind about an answer, put a line through the box and then mark your new answer with a cross . 
The Period 2 element with the highest melting temperature is 
A aluminium 
B boron 
C carbon 
D silicon 
(Total for question = 1 mark
If you need the markscheme, including the examiners' reports for each question, and more exam and teaching materials on this topic, contact me through the contact page
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