Posted in A2 Unit 5: Radioactivity, AQA A2 Unit 5 by Mr A on 20 Jan 2010

$\alpha$ emission

$^{A}_{Z}X \ \rightarrow \ ^{A-4}_{Z-2}Y \ + \ ^{4}_{2}\alpha$

$\beta^{-}$ emission

$^{A}_{Z}X \ \rightarrow \ ^{A}_{Z+1}Y \ + \ ^{0}_{-1}\beta \ + \ \bar{\nu_{e}}$

$\beta^{+}$ emission

$^{A}_{Z}X \ \rightarrow \ ^{A}_{Z-1}Y \ + \ ^{0}_{1}\beta \ + \ \nu_{e}$

Electron capture

$^{A}_{Z}X \ + \ ^{0}_{-1}e \rightarrow \ ^{A}_{Z-1}Y \ + \ \nu_{e}$

$\gamma$ emission

$^{A}_{Z}X \ \rightarrow \ ^{A}_{Z}X \ + \ ^{0}_{0}\gamma$

Posted in A2 Unit 5: Radioactivity, AQA A2 Unit 5 by Mr A on 6 Jan 2010
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This experiment investigates the random nature of radioactivity by studying the nature of another random process, rolling several dice at once. After each roll a certain number is removed (based on the ‘instability’ of the atoms we are modelling). The decay pattern follows an exponential decline, given by

$N = N_{0} e^{- \lambda t}$

Taking logs of both sides we find:

$ln|N| = ln|N_{0}| - \lambda t$

This means that if we plot a graph of ln|N| against t, we should find a straight line with gradient λ.

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