radioactivity in medicine

• how does a pet scanner work

  radioactive tracer taken which emits beta radiation , it collides with another neutron and causes annihlation which releases gamma rays , these gamma rays are then detected by specialist cameras which move around the body during a pet scan creating an image of the persons body
• isotopes are used in pet scanners , what is important about where they are produced and why

  they must be produced near the hospital because the isotopes used have a short life meaning they must be used soon after production
• describe the advantages of nuclear power for generating electricity

  nuclear fuels do not produce carbon dioxide , the fuel is readily available , so would reduce the strain on fossil fuel supplies , less nuclear fuel has to be used to produce the same amount of energy as burning fossil fuels , does not contribute to global warming
• explain some disadvantages of using nuclear power to generate electricity

  unpopular , security risks as radioactive substances can be useful for terrorists , expensive to commision and decommison the stations , which may be bad for the countrys economy , the radioactive waste can be difficult to dispose of and will remain radioactive for many years , which can be dangerous and harm the environment , risk of nuclear accidents
• what technique is used to detect objects in deep water and measure water depth

  echo sounding , high frequency sound waves are emitted by the boat are sent to the sea bed and reflected back , measure time between the initial pulse and the echo returning by using a specialist microphone or stop watch , using your information , carry out the equation distance = speed x time and half the value as it only took half the time to reach the bottom of the pool