Half-life and activity Flashcards

1
Q

What can be noted about the decay of nuclei (timing)

A
  • We cannot predict when a radioactive isotope would decay as it is completely random
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2
Q

What is the activity of a radioactive substance

A
  • The overall rate of decay of all of the isotopes in a sample
  • The number of decays per second in a sample
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3
Q

What is the half-life of a radioactive substance

A
  • The amount of time taken or the number of radioactivve nuclei in a sample to halve
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4
Q

What happens to the activity of a substance as the number of unstable nuclei decreases and why

A
  • The activity of the substance will also decrease
  • This is not because the nuclei are decaying more slowly
  • This is because there are less overall nuclei to decay
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5
Q

What is radioactive activity measured in

A
  • Becquerels
  • 1 becquerel = 1 decay per second
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6
Q

What is radioactivity measured using

A
  • Geiger counter
  • Records decays per second
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7
Q

What is the corrected count rate of a geiger counter

A
  • Corrected count rate = count rate - background count
  • Measure background count with no source present
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