nuclear radiation

• describe isotope

  atoms of an element with same atomic number / number of protons and different mass number / number of neutrons
• describe radioactive decay

  random process where unstable nuclei emit radiation to become more stable
• give types of emitted nuclear radiation

  alpha particle, beta particle, gamma ray and neutron
• give components of alpha particle radiation

  two protons and two neutrons
• give ionising power of alpha particle

  strong
• give range of alpha particle in air

  few cm
• give penetrating power of alpha particle

  weak - absorbed by piece of paper
• give components of beta particle

  electron as neutron turns to proton
• give ionising power of beta particle

  moderate
• give range of beta particle in air

  few m
• give penetrating power of beta particle

  moderate - absorbed by sheet of aluminium
• give components of gamma ray

  electromagnetic radiation
• give ionising power of gamma ray

  weak
• give range of gamma ray in air 


  very long distance
• give penetrating power of gamma ray

  strong - absorbed by thick sheet of concrete or lead
• describe activity

  rate at which unstable nuclei decay
• describe count rate

  number of decays per second measured with detector ( geiger mulelr tube)
• describe half life

  time taken for number of nuclei in sample to halve or count rate to halve from initial level
• give uses of nuclear radiation

  exploration of internal organs and control or destruct unwanted tissue
• describe exploration of internal organs

  gamma rays used for medical tracers of body followed with external detector
• describe control or destruction of unwanted tissue

  gamma rays directed to areas to kill cancer cells and treat cancer
• give dangers of use of nuclear radiation

  • ionise cells causing tissue damage
  • uncontrolled cell division causing cancer
  • kill cells causing radiation sickness