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2 marksRadioactivity

CAPE Physics Unit 2 · 2009 · Paper 2 · Question 6(b)(ii)

Sodium-24 has a molar mass of 24 g/mol and beta-decays with a half-life of 15.0 hours.

Calculate the number of atoms present in a 1.0 mg sample of sodium-24.

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Other parts of this question

  1. 6(a)Explain the terms 'decay constant' (lambda) and 'half life' (T_1/2). Starting with N = N0 * e^(-lambda * t), derive an equation relating these two quantities.[5 marks]
  2. 6(b)(i)Calculate the decay constant in units of s^-1.[1 mark]
  3. 6(b)(iii)Calculate the activity of a 1.0 mg pure sample of sodium-24.[2 marks]
  4. 6(c)A small volume of sodium-24 solution having an initial activity of 1.2 * 10^4 disintegrations per minute was injected into a patient's bloodstream. After 30…[5 marks]

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