Lesson 11.8 • Competencies 11.1–11.7Interactive Simulation

Unit 11 Summative Assessment: Matter & Radiation

Comprehensive 20-question examination testing all 7 competencies in Unit 11 (Black-body radiation, photoelectric effect, de Broglie matter waves, X-rays, radioactive decay, nuclear energy, and Standard Model fundamental particles) with instant competency diagnostic feedback.

Marking a lesson complete represents finishing your study of the topic; it does not denote tested mastery.

Learning Objectives

Synthesize quantum, atomic, nuclear, and particle physics concepts under timed examination conditions.
Identify personal competency strengths and areas requiring revision across syllabus topics 11.1 to 11.7.

Core Theory & Concepts

This summative assessment evaluates your complete mastery of Unit 11 (Matter and Radiation). You will answer 20 questions representing standard Sri Lankan G.C.E. A/L exam patterns with an automated diagnostic report at the end.

Examination Strategy

Ensure all units are converted to standard SI (Joules, meters, seconds, kg) before using formulas, and convert back to eV or nm where requested.

Common Misconceptions

Misconception

Leaving questions blank avoids penalties in A/L Physics assessments.

Physical Clarification:In Sri Lankan A/L examinations, there is no negative marking for incorrect attempts. Always provide your most reasoned response.

Syllabus Topic Outline

Competencies 11.1–11.7

1Summative questions covering Competencies 11.1 - 11.7
2Structured essay questions with point-by-point marking rubrics
3Instant diagnostic competency mastery scoring
4Step-by-step physical solution walkthroughs

Unit 11 Comprehensive Assessment: Matter and Radiation

Summative examination covering all 4 syllabus competencies (11.1 to 11.4): photoelectric effect & photons, de Broglie matter waves & X-rays, Bohr atomic model & spectral series, and nuclear radioactivity & mass-energy equivalence.

Answered: 0 / 20

1Competency 11.1: Black-Body Radiation & Quantum Theoryfoundation • mcq

According to Einstein’s photon theory, when the frequency of monochromatic light incident on a metal surface is doubled while maintaining constant intensity, which of the following statements is true?

2Competency 11.1: Black-Body Radiation & Quantum Theoryfoundation • mcq

Which of the following experimental facts cannot be explained by classical wave theory of light?

3Competency 11.2: Photoelectric Effect & Photonsfoundation • mcq

An electron and an alpha particle have the same kinetic energy. What is the ratio of the de Broglie wavelength of the electron to that of the alpha particle?

4Competency 11.2: Photoelectric Effect & Photonsintermediate • mcq

In an X-ray tube operated at accelerating voltage V, the minimum cutoff wavelength λ_min of continuous Bremsstrahlung X-rays depends on V according to:

5Competency 11.3: Wave-Particle Dualityfoundation • mcq

Which of the following is Bohr’s angular momentum quantization postulate for an electron in a stable hydrogen stationary orbit of principal quantum number n?

6Competency 11.3: Wave-Particle Dualityfoundation • mcq

In the hydrogen emission spectrum, which spectral series falls within the visible region of electromagnetic radiation?

7Competency 11.5: Atomic Models & Line Spectrafoundation • mcq

A radioactive isotope has a decay constant λ. What is its half-life T_½?

8Competency 11.5: Atomic Models & Line Spectraintermediate • mcq

Which type of nuclear radiation has the highest specific ionization power and the lowest penetration depth in matter?

9Competency 11.5: Atomic Models & Line Spectraintermediate • mcq

A radioactive sample has an activity of 800 Bq initially. After 24 days, its activity drops to 100 Bq. What is the half-life of this isotope?

10Competency 11.6: Nuclear Physics, Binding Energy, Fission & Fusionfoundation • mcq

The nuclear radius R of an atom with mass number A is proportional to:

11Competency 11.6: Nuclear Physics, Binding Energy, Fission & Fusionintermediate • mcq

Why is energy released during both nuclear fission of very heavy nuclei (e.g. U-235) and nuclear fusion of very light nuclei (e.g. H-2)?

12Competency 11.6: Nuclear Physics, Binding Energy, Fission & Fusionfoundation • mcq

The atomic mass unit (1 u) is defined as exactly 1/12 the mass of an unbound atom of:

13Competency 11.1: Black-Body Radiation & Quantum Theoryintermediate • numerical

Calculate the threshold frequency (in units of 10¹⁴ Hz) for a photosensitive metal having a work function of 2.48 eV. (Take h = 6.63 × 10⁻³⁴ J s, e = 1.60 × 10⁻¹⁹ C)

10¹⁴ Hz

14Competency 11.2: Photoelectric Effect & Photonsintermediate • numerical

Calculate the de Broglie wavelength of an electron accelerated from rest across a potential difference of 150 V (in picometers, pm). (Take h = 6.63 × 10⁻³⁴ J s, m_e = 9.11 × 10⁻³¹ kg, e = 1.60 × 10⁻¹⁹ C)

15Competency 11.3: Wave-Particle Dualityintermediate • numerical

Calculate the wavelength (in nanometers, nm) of the H-alpha red spectral line in the Balmer series of hydrogen (transition from n=3 to n=2). (Take Rydberg constant R_H = 1.097 × 10⁷ m⁻¹)

16Competency 11.5: Atomic Models & Line Spectraintermediate • numerical

A sample contains 1.6 × 10¹⁰ radioactive nuclei with a half-life of 20 seconds. What is the initial activity of the sample in units of 10⁸ Bq? (Take ln 2 ≈ 0.693)

10⁸ Bq

17Competency 11.5: Atomic Models & Line Spectraadvanced • numerical

Carbon-14 has a half-life of 5730 years. An ancient wooden artifact has a C-14 activity that is 25% of the activity in living wood. What is the age of the artifact in years?

years

18Competency 11.6: Nuclear Physics, Binding Energy, Fission & Fusionintermediate • numerical

Calculate the total binding energy (in MeV) of a Helium-4 nucleus (⁴He) having a mass defect of 0.03038 u. (Take 1 u = 931.5 MeV)

MeV

19Competency 11.6: Nuclear Physics, Binding Energy, Fission & Fusionintermediate • numerical

For the Helium-4 nucleus with a total binding energy of 28.3 MeV, calculate its binding energy per nucleon (in MeV/nucleon).

MeV/nucleon

20Competency 11.6: Nuclear Physics, Binding Energy, Fission & Fusionadvanced • numerical

In a nuclear fission event: ²³⁵U + n → ¹⁴¹Ba + ⁹²Kr + 3n, the mass defect is 0.215 u. Calculate the energy released in this single fission event in MeV. (Take 1 u = 931.5 MeV)

MeV