Radioactivity and particles

Worked examples (9)

• 1Describe the method (Getting started)
• 2Why subtract background (Getting started)
• 3State the variables (Getting started)
• 4Identify the source (Building confidence)
• 5A source emitting two radiations (Building confidence)
• 6The shape of the graph (Building confidence)
• 7Safety precautions with reasons (Stretch)
• 8Evaluate a flawed procedure (Stretch)
• 9Real source or simulation? (Stretch)

Model answers (9)

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Worked examples (9)

• 1What activity means (Getting started)
• 2Counts per minute to becquerels (Getting started)
• 3Prefix conversions (Getting started)
• 4Half-life units cancel (Building confidence)
• 5Subtracting background (Building confidence)
• 6Activity is not amount (Building confidence)
• 7Centimetres for range (Stretch)
• 8Spot the implausible value (Stretch)
• 9A full unit audit (Stretch)

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Worked examples (9)

• 1The three particles (Getting started)
• 2Read the notation (Getting started)
• 3Write the notation (Getting started)
• 4Identify the isotopes (Building confidence)
• 5Why isotopes share chemistry (Building confidence)
• 6Forming an ion (Building confidence)
• 7Mass and volume of the atom (Stretch)
• 8Particles in nuclear notation (Stretch)
• 9Deduce the nucleus (Stretch)

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Worked examples (9)

• 1The nature of each radiation (Getting started)
• 2Penetration and ionisation (Getting started)
• 3Why the orders are inverse (Getting started)
• 4Balance an alpha decay (Building confidence)
• 5Balance a beta decay (Building confidence)
• 6Identify the decay type (Building confidence)
• 7Find the missing particle (Stretch)
• 8Inside or outside the body (Stretch)
• 9Deflection in a magnetic field (Stretch)

Model answers (9)

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Worked examples (9)

• 1The two detectors (Getting started)
• 2How a GM tube works (Getting started)
• 3Sources of background radiation (Getting started)
• 4Choose the right detector (Building confidence)
• 5Natural and artificial sources (Building confidence)
• 6Why background varies (Building confidence)
• 7Film badge windows (Stretch)
• 8Correcting for background (Stretch)
• 9Compare the two detectors (Stretch)

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Worked examples (9)

• 1Define half-life (Getting started)
• 2Activity after a given time (Getting started)
• 3The fraction remaining (Getting started)
• 4Find the time elapsed (Building confidence)
• 5Find the half-life (Building confidence)
• 6Read the half-life from a graph (Building confidence)
• 7How many nuclei have decayed (Stretch)
• 8Plotting a decay curve from data (Stretch)
• 9What does not affect half-life (Stretch)

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Worked examples (9)

• 1Why gamma for a medical tracer (Getting started)
• 2The paper thickness gauge (Getting started)
• 3The smoke detector (Getting started)
• 4Radiotherapy (Building confidence)
• 5Sterilising equipment (Building confidence)
• 6A gauge for steel sheet (Building confidence)
• 7Detecting a leak in a buried pipe (Stretch)
• 8Carbon dating (Stretch)
• 9Weighing risk against benefit (Stretch)

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Worked examples (9)

• 1The two biological effects (Getting started)
• 2Why radiation is harmful (Getting started)
• 3Mutations and cancer (Getting started)
• 4Why waste disposal is difficult (Building confidence)
• 5How high-level waste is disposed of (Building confidence)
• 6Reducing the risk (Building confidence)
• 7Precautions in a hospital (Stretch)
• 8Weighing risk against benefit (Stretch)
• 9Monitoring cumulative dose (Stretch)

Model answers (9)

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Worked examples (9)

• 1The fission sequence (Getting started)
• 2Why a neutron? (Getting started)
• 3The products of fission (Getting started)
• 4Balance a fission equation (Building confidence)
• 5Find the missing daughter nucleus (Building confidence)
• 6In what form is the energy released? (Building confidence)
• 7Why fission can sustain itself (Stretch)
• 8Why uranium is enriched (Stretch)
• 9Write a complete fission equation (Stretch)

Model answers (9)

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Worked examples (9)

• 1Why nuclei repel (Getting started)
• 2The two conditions (Getting started)
• 3Why fusion fails at low temperature and pressure (Getting started)
• 4How stars achieve the conditions (Building confidence)
• 5Why fusion is difficult on Earth (Building confidence)
• 6Why fission needs no such conditions (Building confidence)
• 7Why hydrogen is used (Stretch)
• 8Why fusion cannot run away (Stretch)
• 9The complete explanation (Stretch)

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Worked examples (9)

• 1Define both terms (Getting started)
• 2Classify the situations (Getting started)
• 3Is irradiated food radioactive? (Getting started)
• 4The alpha reversal (Building confidence)
• 5Which hazard is worse? (Building confidence)
• 6Match the precaution to the hazard (Building confidence)
• 7Radon in the home (Stretch)
• 8Why school sources are sealed (Stretch)
• 9Stopping each hazard (Stretch)

Model answers (9)

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Worked examples (9)

• 1The three nuclear reactions (Getting started)
• 2Fission or fusion? (Getting started)
• 3Nuclear versus chemical (Getting started)
• 4Generating electricity from fission (Building confidence)
• 5How the energy appears (Building confidence)
• 6Why spacecraft use radioactive decay (Building confidence)
• 7Evaluating nuclear power (Stretch)
• 8Why fusion is not yet used (Stretch)
• 9Classify the reactions (Stretch)

Model answers (9)

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Worked examples (9)

• 1Describe a chain reaction (Getting started)
• 2The steady-state condition (Getting started)
• 3The moderator (Getting started)
• 4The control rods (Building confidence)
• 5Moderator or control rod? (Building confidence)
• 6Why shielding is needed (Building confidence)
• 7The complete reactor (Stretch)
• 8What happens to the released neutrons (Stretch)
• 9Radiation safety at a power station (Stretch)

Model answers (9)

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Worked examples (9)

• 1Fusion or fission? (Getting started)
• 2Mass loss in fusion (Getting started)
• 3The Sun's energy source (Getting started)
• 4Why stars can achieve fusion (Building confidence)
• 5The full comparison (Building confidence)
• 6Classify the reactions (Building confidence)
• 7Why both release energy (Stretch)
• 8Energy on Earth from fusion (Stretch)
• 9Why a star stays the same size (Stretch)

Model answers (9)

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