RADIOACTIVITY

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RADIOACTIVITY
BY MARTIN, HAYLEY AND DAVID
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HISTORY

• Alpha and Beta particles or Gamma rays can be
  omitted from Radioactive sources.
• All three are ionising, this means to pull of an
  electron from another atom that is passed.
• Alpha particles are the most ionising but have
  the lowest penetrating power, they can be stopped
  by paper
• Beta particles can be stopped by a thin sheet of
  aluminium
• Gamma rays need much lead to be stopped.

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SOURCES OF RADIATION

• Background radioactivity is mainly natural
  radioactivity,
• the vast majority of our annual dose comes from
  radon gas, food drink, the ground, and cosmic
  rays (which are gamma rays coming in from space).

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USES OF RADIOACTIVE SOURCES

• Smoke alarms
• Sterilising hospital equipment
• Thickness control
• Radioactive dating
• Radioactive tracers
• Cancer treatment

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HALF LIFE

• A Geiger counters reading, when pointed at a
  radioactive source, decreases over a period of
  time
• Some substances radioactivity dies away very fast
  microseconds, Others can take thousands of
  years
• We use half life to determine the rate at which a
  substance gives off radiation
• Half life is the time it takes for the
  radioactivity to fall by half

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DANGERS OF RADIOACTIVITY

• The main danger from radioactivity is the damage
  done to cells in your body from ionising
  radiation
• Ionisation is when an Alpha or Beta particle
  passes another atom and pulls an electron from it
• When this happens we say the atom has been
  ionised
• If this happens to part of a cell in your body
  such as DNA the coding can be damaged, leading to
  mutations