Nuclear Energy

What Nuclear Energy covers

Nuclear Energy is examined in Component 3, Light, Nuclei and Options, Section A, which every student sits. It covers mass–energy equivalence and E = Δmc², mass defect, binding energy and the unified atomic mass unit, calculating binding energy per nucleon, the binding energy per nucleon curve and fission, fusion and the nuclear power debate.

The 5 subtopics

Each one has its own page.

• Mass–energy equivalence and E = Δmc²Mass–energy equivalence and unified atomic mass unit.Open →
• Mass defect, binding energy and the unified atomic mass unitMass defect of a nucleus, binding energy of a nucleus and binding energy per nucleon.Open →
• Calculating binding energy per nucleonRecall questions on finding the mass defect from the constituent masses, converting it to an energy with E = Δmc², dividing by the nucleon number, the unified atomic mass unit and its energy equivalent, and worked determinations for named nuclides.Open →
• The binding energy per nucleon curveRecall questions on the shape of the curve and what goes on each axis, which nuclide sits at the peak and what that means for stability, why fusion of light nuclei and fission of heavy nuclei both release energy, and reading an energy release from two points on it.Open →
• Fission, fusion and the nuclear power debateNuclear fission, nuclear fusion and what a chain reaction is in a fission reactor.Open →

What you need to know

Answer each one before you reveal it.

Take Nuclear Energy further

The same content, four other ways.

Questions from this topic

Each one with the model answer underneath.

1. 1

   State the equation linking mass and energy, defining each symbol and its unit.

   Model answer

   The equation is E = mc². E is the energy in J, m is the mass in kg and c is the speed of light in free space, 3.00 × 10⁸ m s⁻¹.

2. 2

   What does mass–energy equivalence mean?

   Model answer

   It means mass and energy are two forms of the same thing and can be converted into one another. Any change in the energy of a system is accompanied by a change in its mass.

3. 3

   Write the mass–energy equation in the form used for a change of mass, and say what it gives.

   Model answer

   The form is ΔE = Δmc². It gives the energy released or absorbed when the mass of a system changes by Δm.

4. 4

   Calculate the energy equivalent of a mass of 1.0 kg.

   Model answer

   E = mc² = 1.0 × (3.00 × 10⁸)² = 9.0 × 10¹⁶ J. Dividing 9.0 × 10¹⁶ J by (3.00 × 10⁸ m s⁻¹)² returns the 1.0 kg.

5. 5

   Why is a change of mass never noticed in a chemical reaction?

   Model answer

   Chemical energies are only a few eV per particle, and dividing that by c² gives a mass change far too small to detect. A nuclear reaction releases roughly a million times more energy per particle, so its mass change is measurable.

6. 6

   Define the unified atomic mass unit.

   Model answer

   The unified atomic mass unit is exactly one twelfth of the mass of a neutral atom of carbon-12. Its symbol is u and its value is 1.66 × 10⁻²⁷ kg.

What is inside Levo

Six ways to work the same material.

Nuclear Energy revision questions

What does Nuclear Energy cover in Eduqas A-Level Physics?

5 subtopics: mass–energy equivalence and e = δmc², mass defect, binding energy and the unified atomic mass unit, calculating binding energy per nucleon, the binding energy per nucleon curve and fission, fusion and the nuclear power debate. Each one has its own page with questions and model answers.

How is Nuclear Energy organised?

By the Eduqas A420QS specification, subtopic by subtopic, so it matches the order you are taught it in.