For Examiners Use - Materials For this paper you must have: • a p...

*JUN25 7408201*

IB/M/Jun25/G4006/E12 7408/2

For Examiner’s Use Question Mark 1 2 3 4 5 6

7–31

TOTAL

Monday 9 June 2025 Morning Time allowed: 2 hours

Materials

For this paper you must have:

• a pencil and a ruler • a scientific calculator • a Data and Formulae Booklet • a protractor.

Instructions • Use black ink or black ball-point pen.• Fill in the boxes at the top of this page.• Answer all questions.• You must answer the questions in the spaces provided. Do not write 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 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 85.• You are expected to use a scientific calculator where appropriate.• A Data and Formulae Booklet is provided as a loose insert.Please write clearly in block capitals.Centre number

Candidate number

Surname

Forename(s)

Candidate signature

I declare this is my own work.A-level

PHYSICS

Paper 2 1 / 4

2

*02* IB/M/Jun25/ 7408/2

Do not write outside the box Section A

Answer all questions in this section.

• 1

Information about the radius of a nucleus can be deduced from the closest approach of alpha particles and from electron diffraction.

• 1

. 1 Alpha particles, each with a kinetic energy of 5.59 MeV, are fired at a thin foil made of gold ( ) 197 Au 79 atoms.Some of the alpha particles are scattered through an angle of 180°.

Estimate the radius of a 197 Au 79 nucleus from this information.[3 marks]

radius of nucleus =

m

• 1

. 2 Explain why your answer to Question 01.1 is an estimate.[2 marks]

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3

*03* Turn over ►

IB/M/Jun25/7408/ 2

Do not write outside the box

• 1

. 3

Electron diffraction gives a more precise value for the radius of the nucleus.

Sketch, on Figure 1, a graph of intensity against angle for electron diffraction by a nucleus.Go on to state the feature of this graph that is used to determine the radius of the nucleus.[2 marks]

Figure 1

Question 1 continues on the next page

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4

*04* IB/M/Jun25/7408/ 2

Do not write outside the box

• 1

. 4

Results from electron-diffraction experiments lead to the equation:

1 3

=R RA

Show that the equation provides evidence for the constant density of nuclear material.[2 marks]

9

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