Monday 15 June 2026 – Morning
A Level Chemistry A
H432/03 Unified chemistry
Time allowed: 1 hour 30 minutes
You must have:
GCE
*
• the Data Sheet for Chemistry A
You can use:
• a scientific or graphical calculator
• an HB pencil
Chemistry A
H432/03: Unified chemistry
* H 4 3 2 0 3 *
*
Please write clearly in black ink. Do not write in the barcodes. A Level
Centre number Candidate number
Mark Scheme for June 2026
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 70.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 20 pages.
ADVICE
• Read each question carefully before you start your answer.
Cambridge 2026 [601/5255/2] Cambridge is an exempt Charity
DC (ST/SG) 362811/7 Turn over
Cambridge
, 2
1 This question is about the first 36 elements in the periodic table, and their compounds. The first
36 elements are shown in Figure 1.1.
Figure 1.1
Cambridge is a leading UK awarding body, providing a wide range of qualifications to
meet the needs of candidates of all ages and abilities. Cambridge qualifications include
H He AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals, Functional Skills,
Key Skills, Entry Level qualifications, NVQs and vocational qualifications in areas such as IT,
Li Be B C N O F Ne business, languages, teaching/training, administration and secretarial skills.
Na Mg Al Si P S Cl Ar It is also responsible for developing new specifications to meet national requirements and the
needs of students and teachers. Cambridge is a not-for-profit organisation; any surplus
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr made is invested back into the establishment to help towards the development of qualifications
and support, which keep pace with the changing needs of today’s society.
(a) Chemists used to order elements in the periodic table by increasing atomic mass, but this
This mark scheme is published as an aid to teachers and students, to indicate the requirements
method has changed over time.
of the examination. It shows the basis on which marks were awarded by examiners. It does not
Identify two pairs of elements in Figure 1.1 that do not fit into ordering the elements by indicate the details of the discussions which took place at an examiners’ meeting before marking
increasing atomic mass, and explain how these elements are now arranged. commenced.
Pair 1 ................... and ................... Pair 2 ................... and ................... All examiners are instructed that alternative correct answers and unexpected approaches in
candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills
Explanation: ..................................................................................................................................... demonstrated.
.......................................................................................................................................................... Mark schemes should be read in conjunction with the published question papers and the report
[2] on the examination.
(b) State two elements from the first 3 periods (H Ar) in Figure 1.1 that have a giant covalent
lattice structure. Cambridge 2026
.......................... and .......................... [1]
Which element in Figure 1.1 has the smallest first ionisation energy?
.......................... [1]
(d) State the three elements from Period 4 (K Kr) that have atoms where only three electrons
are unpaired.
.......................... and .......................... and .......................... [2]
Cambridge 2026
Cambridge
, H432/03 Mark Scheme June 2026
3
(e) Element M is a transition element in Figure 1.1.
Marking Instructions
1.20 g of element M reacts with O2 to form 1.80 g of M2O3.
Preparation For Marking
Determine by calculation the identity of element M.
1. RM Assessor
• Access and complete the on-screen marking training packages: Examiner Training (RMA3).
• Read the mark scheme and question paper for this component or unit.
• The mark scheme and question paper are available in RM Assessor or on your Component Page if you use the Training Platform for
standardisation.
• Log in to RM Assessor and mark the required number of practice scripts and the required number of standardisation scripts.
Marking
2. General Guidance
Element M: ......................................................... [3]
• Mark strictly to the mark scheme.
(f) The table shows boiling points of hydrides of elements from Figure 1.1.
Boiling point Boiling point • Marks awarded must relate directly to the marking criteria.
Hydride Hydride
/K /K
• If you are in any doubt about applying the mark scheme, consult your Team Leader by phone, email or via the RM Assessor messaging
Period 2 CH4 112 NH3 240 system.
Period 3 SiH4 161 PH3 185
• It is essential that you meet the RM Assessor 50% and 100% batch deadlines. For traditional marking this will be 40% and 100%. If you
experience problems, contact your Team Leader without delay.
Explain the following.
• Always check the pages (and additional objects if present) at the end of the response in case any answers have been continued there. If the
• The boiling point of SiH4 is higher than the boiling point of CH4.
candidate has continued an answer there, then add the annotation ‘SEEN’ to confirm that the work has been seen and mark any responses
• The boiling point of NH3 is higher than the boiling point of PH3. using the annotations in Section 6.
..........................................................................................................................................................
2
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..................................................................................................................................................... [4]
Cambridge 2026 Turn over
A Level Chemistry A
H432/03 Unified chemistry
Time allowed: 1 hour 30 minutes
You must have:
GCE
*
• the Data Sheet for Chemistry A
You can use:
• a scientific or graphical calculator
• an HB pencil
Chemistry A
H432/03: Unified chemistry
* H 4 3 2 0 3 *
*
Please write clearly in black ink. Do not write in the barcodes. A Level
Centre number Candidate number
Mark Scheme for June 2026
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined pages at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 70.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 20 pages.
ADVICE
• Read each question carefully before you start your answer.
Cambridge 2026 [601/5255/2] Cambridge is an exempt Charity
DC (ST/SG) 362811/7 Turn over
Cambridge
, 2
1 This question is about the first 36 elements in the periodic table, and their compounds. The first
36 elements are shown in Figure 1.1.
Figure 1.1
Cambridge is a leading UK awarding body, providing a wide range of qualifications to
meet the needs of candidates of all ages and abilities. Cambridge qualifications include
H He AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals, Functional Skills,
Key Skills, Entry Level qualifications, NVQs and vocational qualifications in areas such as IT,
Li Be B C N O F Ne business, languages, teaching/training, administration and secretarial skills.
Na Mg Al Si P S Cl Ar It is also responsible for developing new specifications to meet national requirements and the
needs of students and teachers. Cambridge is a not-for-profit organisation; any surplus
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr made is invested back into the establishment to help towards the development of qualifications
and support, which keep pace with the changing needs of today’s society.
(a) Chemists used to order elements in the periodic table by increasing atomic mass, but this
This mark scheme is published as an aid to teachers and students, to indicate the requirements
method has changed over time.
of the examination. It shows the basis on which marks were awarded by examiners. It does not
Identify two pairs of elements in Figure 1.1 that do not fit into ordering the elements by indicate the details of the discussions which took place at an examiners’ meeting before marking
increasing atomic mass, and explain how these elements are now arranged. commenced.
Pair 1 ................... and ................... Pair 2 ................... and ................... All examiners are instructed that alternative correct answers and unexpected approaches in
candidates’ scripts must be given marks that fairly reflect the relevant knowledge and skills
Explanation: ..................................................................................................................................... demonstrated.
.......................................................................................................................................................... Mark schemes should be read in conjunction with the published question papers and the report
[2] on the examination.
(b) State two elements from the first 3 periods (H Ar) in Figure 1.1 that have a giant covalent
lattice structure. Cambridge 2026
.......................... and .......................... [1]
Which element in Figure 1.1 has the smallest first ionisation energy?
.......................... [1]
(d) State the three elements from Period 4 (K Kr) that have atoms where only three electrons
are unpaired.
.......................... and .......................... and .......................... [2]
Cambridge 2026
Cambridge
, H432/03 Mark Scheme June 2026
3
(e) Element M is a transition element in Figure 1.1.
Marking Instructions
1.20 g of element M reacts with O2 to form 1.80 g of M2O3.
Preparation For Marking
Determine by calculation the identity of element M.
1. RM Assessor
• Access and complete the on-screen marking training packages: Examiner Training (RMA3).
• Read the mark scheme and question paper for this component or unit.
• The mark scheme and question paper are available in RM Assessor or on your Component Page if you use the Training Platform for
standardisation.
• Log in to RM Assessor and mark the required number of practice scripts and the required number of standardisation scripts.
Marking
2. General Guidance
Element M: ......................................................... [3]
• Mark strictly to the mark scheme.
(f) The table shows boiling points of hydrides of elements from Figure 1.1.
Boiling point Boiling point • Marks awarded must relate directly to the marking criteria.
Hydride Hydride
/K /K
• If you are in any doubt about applying the mark scheme, consult your Team Leader by phone, email or via the RM Assessor messaging
Period 2 CH4 112 NH3 240 system.
Period 3 SiH4 161 PH3 185
• It is essential that you meet the RM Assessor 50% and 100% batch deadlines. For traditional marking this will be 40% and 100%. If you
experience problems, contact your Team Leader without delay.
Explain the following.
• Always check the pages (and additional objects if present) at the end of the response in case any answers have been continued there. If the
• The boiling point of SiH4 is higher than the boiling point of CH4.
candidate has continued an answer there, then add the annotation ‘SEEN’ to confirm that the work has been seen and mark any responses
• The boiling point of NH3 is higher than the boiling point of PH3. using the annotations in Section 6.
..........................................................................................................................................................
2
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..................................................................................................................................................... [4]
Cambridge 2026 Turn over
