A-LevelPhysicsNuclear physicsMay/June 2018Paper 4 Q138 Marks
13 (a) State what is meant by radioactive decay. (b) The variation with time t of the number N of technetium-101 nuclei in a sample of radioactive material is shown in Fig. 13.1. [Figure 13.1] (i) Use Fig. 13.1 to determine the activity, in Bq, of the sample of technetium-101 at time t = 14.0 minutes. Show your working. activity = .............................................. Bq (ii) Without calculating the half-life of technetium-101, use your answer in (i) to determine the decay constant λ of technetium-101. λ = .............................................. s⁻¹
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
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