5.4 - Nuclear Decay

Understand the concept of nuclear binding energy and be able to use the equation ΔE = c2Δm in calculations of nuclear mass (including mass deficit) and energy.

Use - nuclear binding energy to connect the rule to the data and decision in the question.

This matters because - nuclear binding energy determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - nuclear binding energy to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Nuclear binding energy is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Use the atomic mass unit (u) to express small masses and convert between this and SI units.

Use - atomic mass unit to connect the rule to the data and decision in the question.

This matters because - atomic mass unit determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - atomic mass unit to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Atomic mass unit is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the processes of nuclear fusion and fission with reference to the binding energy per nucleon curve.

Use - nuclear fusion, fission and binding energy to connect the rule to the data and decision in the question.

This matters because - nuclear fusion, fission and binding energy determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - nuclear fusion, fission and binding energy to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Nuclear fusion, fission and binding energy is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the mechanism of nuclear fusion and the need for very high densities of matter and very high temperatures to bring about and maintain nuclear fusion.

Use - fusion conditions to connect the rule to the data and decision in the question.

This matters because - fusion conditions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - fusion conditions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Fusion conditions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand that there is background radiation and how to take appropriate account of it in calculations.

Use - background radiation to connect the rule to the data and decision in the question.

This matters because - background radiation determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - background radiation to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Background radiation is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the relationships between the nature, penetration, ionising ability and range in different materials of nuclear radiations (alpha, beta and gamma).

Use - nuclear radiation properties to connect the rule to the data and decision in the question.

This matters because - nuclear radiation properties determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - nuclear radiation properties to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Nuclear radiation properties is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to write and interpret nuclear equations given the relevant particle symbols.

Use - nuclear equations to connect the rule to the data and decision in the question.

This matters because - nuclear equations determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - nuclear equations to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.

CORE PRACTICAL 15: Investigate the absorption of gamma radiation by lead.

Use - core practical 15 - gamma absorption by lead to connect the rule to the data and decision in the question.

This matters because - core practical 15 - gamma absorption by lead determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - core practical 15 - gamma absorption by lead to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Core Practical 15 - gamma absorption by lead is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the spontaneous and random nature of nuclear decay.

Use - spontaneous and random nuclear decay to connect the rule to the data and decision in the question.

This matters because - spontaneous and random nuclear decay determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - spontaneous and random nuclear decay to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: - Spontaneous and random nuclear decay is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Determine half-life graphically and use A = λN, dN/dt = −λN, λ = ln 2/t½, N = N0e^(−λt), and A = A0e^(−λt), including the corresponding logarithmic equations.

Use - half-life and radioactive decay equations to connect the rule to the data and decision in the question.

This matters because - half-life and radioactive decay equations determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply - half-life and radioactive decay equations to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.