topic 4 - atomic stucture

• Cells that receive a large dosage of radiation could die
• Radiation sickness is an illness caused by being exposed to large amounts of radiation.
• 3 symptoms of radiation sickness are; vomiting, tiredness, hair loss
• Low levels of radiation can cause mutations in our DNA, which may cause our cells to divide uncontrollably.
• What is radiotherapy? 


  the use of targeted doses of radiation to kill cancerous cells
• radiotherapy can be used to treat cancer
• External radiotherapy is where the cancerous cells are exposed to gamma radiation from outside the body, from many different angles. Only the cancer site gets the highest dose of radiation.
• Internal radiotherapy is where the cancerous cells are exposed to radiation from inside/within the body. The radiation source usually emits beta particles and is placed inside or near the cancer cells.
• Side effects of radiotherapy include: feeling sick or tired
• What is a radioactive medical tracer


  Used to help diagnose medical problems by allowing us to locate or track things such as tumours within the body.
• We usually use isotopes with a short half-life for medical tracers as it means they decay relatively quickly so don't last very long. This minimises the time that the patient is exposed to radiation.
• Medical tracers usually emit gamma radiation as it is only weakly ionising, so it won't damage the patients cells very much.