Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
CHEMISTRY
Paper 1 Inorganic and Physical Chemistry
Tuesday 12 May 2026 Morning Time allowed: 1 hour 30 minutes
Materials
For Examiner’s Use
For this paper you must have:
• the Periodic Table/Data Sheet, provided as an insert (enclosed) Question Mark
• a ruler with millimetre measurements 1
• a scientific calculator, which you are expected to use where appropriate. 2
3
Instructions
• Use black ink or black ball-point pen. 4
• Fill in the boxes at the top of this page. 5
• Answer all questions.
6
• You must answer the questions in the spaces provided. Do not write outside
the box around each page or on blank pages. 7
• If you need extra space for your answer(s), use the lined pages at the end of 8
this book. Write the question number against your answer(s). Section B
• All working must be shown.
• Do all rough work in this book. Cross through any work you do not TOTAL
want to be marked.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 80.
Advice
• You are advised to spend 65 minutes on Section A and 25 minutes on Section B.
*Jun267404101*
7404/1
for more:
IB/M/Jun26/G4003/V5
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 Table 1 shows melting point and electrical conductivity information about
four substances.
Table 1
Substance Melting point / °C Electrical conductivity at 298 K
SiO2 1710 None
SCl2 –121 None
Na2O 1132 None
Mg 650 Good
0 1 . 1 Identify the crystal structure of each substance when it is in the solid state.
Tick ( ) one box for each substance.
[2 marks]
Giant
Substance Ionic Metallic Molecular
covalent
SiO2
SCl2
Na2O
Mg
*02* for more:
IB/M/Jun26/7404/1
, 3
Do not write
outside the
0 1 . 2 Explain why the melting point of SiO2 is higher than the melting point of SCl2 box
[2 marks]
0 1 . 3 Explain why the electrical conductivity of solid Mg is greater than the
electrical conductivity of solid Na2O
[2 marks]
6
Turn over for the next question
Turn over ►
*03* for more:
IB/M/Jun26/7404/1
, 4
Do not write
outside the
0 2 This question is about ionisation energies. box
0 2 . 1 Explain why magnesium has a higher first ionisation energy than sodium.
[2 marks]
0 2 . 2 Explain why aluminium has a lower first ionisation energy than magnesium.
[2 marks]
0 2 . 3 Give the equation, including state symbols, that shows the change that occurs when
the third ionisation energy of silicon is measured.
[1 mark]
*04* for more:
IB/M/Jun26/7404/1
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
CHEMISTRY
Paper 1 Inorganic and Physical Chemistry
Tuesday 12 May 2026 Morning Time allowed: 1 hour 30 minutes
Materials
For Examiner’s Use
For this paper you must have:
• the Periodic Table/Data Sheet, provided as an insert (enclosed) Question Mark
• a ruler with millimetre measurements 1
• a scientific calculator, which you are expected to use where appropriate. 2
3
Instructions
• Use black ink or black ball-point pen. 4
• Fill in the boxes at the top of this page. 5
• Answer all questions.
6
• You must answer the questions in the spaces provided. Do not write outside
the box around each page or on blank pages. 7
• If you need extra space for your answer(s), use the lined pages at the end of 8
this book. Write the question number against your answer(s). Section B
• All working must be shown.
• Do all rough work in this book. Cross through any work you do not TOTAL
want to be marked.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 80.
Advice
• You are advised to spend 65 minutes on Section A and 25 minutes on Section B.
*Jun267404101*
7404/1
for more:
IB/M/Jun26/G4003/V5
, 2
Do not write
outside the
Section A box
Answer all questions in this section.
0 1 Table 1 shows melting point and electrical conductivity information about
four substances.
Table 1
Substance Melting point / °C Electrical conductivity at 298 K
SiO2 1710 None
SCl2 –121 None
Na2O 1132 None
Mg 650 Good
0 1 . 1 Identify the crystal structure of each substance when it is in the solid state.
Tick ( ) one box for each substance.
[2 marks]
Giant
Substance Ionic Metallic Molecular
covalent
SiO2
SCl2
Na2O
Mg
*02* for more:
IB/M/Jun26/7404/1
, 3
Do not write
outside the
0 1 . 2 Explain why the melting point of SiO2 is higher than the melting point of SCl2 box
[2 marks]
0 1 . 3 Explain why the electrical conductivity of solid Mg is greater than the
electrical conductivity of solid Na2O
[2 marks]
6
Turn over for the next question
Turn over ►
*03* for more:
IB/M/Jun26/7404/1
, 4
Do not write
outside the
0 2 This question is about ionisation energies. box
0 2 . 1 Explain why magnesium has a higher first ionisation energy than sodium.
[2 marks]
0 2 . 2 Explain why aluminium has a lower first ionisation energy than magnesium.
[2 marks]
0 2 . 3 Give the equation, including state symbols, that shows the change that occurs when
the third ionisation energy of silicon is measured.
[1 mark]
*04* for more:
IB/M/Jun26/7404/1
