Please write clearly in block capitals.
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
PHYSICS
Paper 1
Wednesday 13 May 2026 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• a pencil and a ruler Question Mark
• a scientific calculator 1
• a Data and Formulae Booklet
2
• a protractor.
3
Instructions
4
• Use black ink or black ball-point pen.
• 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 7
outside the box around each page or on blank pages.
• If you need extra space for your answer(s), use the lined pages at the end of TOTAL
this book. Write the question number against your answer(s).
• Do all rough work in this book. Cross through any work you do not want
to be marked.
• Show all your working.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 70.
• You are expected to use a scientific calculator where appropriate.
• A Data and Formulae Booklet is provided as a loose insert.
*jun *
IB/M/Jun26/G4004/V5 7407/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 The proton number of lead is 82
The mass of a nucleus of one isotope of lead is 3.45 × 10−25 kg.
0 1 . 1 The average mass of a nucleon in this nucleus is 1.7 × 10−27 kg.
Calculate the number of neutrons in this nucleus.
[2 marks]
number of neutrons =
0 1 . 2 Calculate the specific charge of this nucleus.
[1 mark]
specific charge = C kg−1
*02*
IB/M/Jun26/7407/1
, 3
Do not write
outside the
0 1 . 3 This isotope of lead is unstable and undergoes a series of alpha and box
beta-minus decays.
The final product of this series of decays is a stable isotope of lead.
What is the number of alpha and beta-minus decays that occur?
Tick () one box.
[1 mark]
one alpha, one beta minus
one alpha, two beta minus
two alpha, one beta minus
two alpha, two beta minus 4
Turn over for the next question
Turn over ►
*03*
IB/M/Jun26/7407/1
, 4
Do not write
outside the
0 2 An unidentified particle X interacts with a proton to produce a neutron and a positron. box
The equation representing the interaction is
X + p → n + e+
0 2 . 1 State the quark structure of the neutral hadron that is involved in this interaction.
[1 mark]
0 2 . 2 Identify particle X.
Justify your answer by referring to appropriate conservation laws.
[3 marks]
X=
0 2 . 3 The total energy of an interaction consists of the kinetic energy and the mass-energy
of the interacting particles.
A positron is moving very slowly when it interacts with a stationary electron.
The total energy of this interaction is 1.64 × 10−13 J.
Calculate the maximum wavelength of the gamma radiation that is produced when the
positron and electron annihilate.
[2 marks]
maximum wavelength = m 6
*04*
IB/M/Jun26/7407/1
Centre number Candidate number
Surname
Forename(s)
Candidate signature
I declare this is my own work.
AS
PHYSICS
Paper 1
Wednesday 13 May 2026 Morning Time allowed: 1 hour 30 minutes
Materials
For this paper you must have: For Examiner’s Use
• a pencil and a ruler Question Mark
• a scientific calculator 1
• a Data and Formulae Booklet
2
• a protractor.
3
Instructions
4
• Use black ink or black ball-point pen.
• 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 7
outside the box around each page or on blank pages.
• If you need extra space for your answer(s), use the lined pages at the end of TOTAL
this book. Write the question number against your answer(s).
• Do all rough work in this book. Cross through any work you do not want
to be marked.
• Show all your working.
Information
• The marks for questions are shown in brackets.
• The maximum mark for this paper is 70.
• You are expected to use a scientific calculator where appropriate.
• A Data and Formulae Booklet is provided as a loose insert.
*jun *
IB/M/Jun26/G4004/V5 7407/1
, 2
Do not write
outside the
Answer all questions in the spaces provided. box
0 1 The proton number of lead is 82
The mass of a nucleus of one isotope of lead is 3.45 × 10−25 kg.
0 1 . 1 The average mass of a nucleon in this nucleus is 1.7 × 10−27 kg.
Calculate the number of neutrons in this nucleus.
[2 marks]
number of neutrons =
0 1 . 2 Calculate the specific charge of this nucleus.
[1 mark]
specific charge = C kg−1
*02*
IB/M/Jun26/7407/1
, 3
Do not write
outside the
0 1 . 3 This isotope of lead is unstable and undergoes a series of alpha and box
beta-minus decays.
The final product of this series of decays is a stable isotope of lead.
What is the number of alpha and beta-minus decays that occur?
Tick () one box.
[1 mark]
one alpha, one beta minus
one alpha, two beta minus
two alpha, one beta minus
two alpha, two beta minus 4
Turn over for the next question
Turn over ►
*03*
IB/M/Jun26/7407/1
, 4
Do not write
outside the
0 2 An unidentified particle X interacts with a proton to produce a neutron and a positron. box
The equation representing the interaction is
X + p → n + e+
0 2 . 1 State the quark structure of the neutral hadron that is involved in this interaction.
[1 mark]
0 2 . 2 Identify particle X.
Justify your answer by referring to appropriate conservation laws.
[3 marks]
X=
0 2 . 3 The total energy of an interaction consists of the kinetic energy and the mass-energy
of the interacting particles.
A positron is moving very slowly when it interacts with a stationary electron.
The total energy of this interaction is 1.64 × 10−13 J.
Calculate the maximum wavelength of the gamma radiation that is produced when the
positron and electron annihilate.
[2 marks]
maximum wavelength = m 6
*04*
IB/M/Jun26/7407/1
