Radiation

• Radioisotope: unstable, radioactive individual isotopes
• Spontaneous transmutation: the process of an unstable nucleus spontaneously emitting a particle to become more stable. Therefore changing into a different element/isotope
• Artificial transmutation: the altering of lab produced radioisotopes to alter properties for various applications
• Radioactive particles/waves are ionizing
• Label

  A)

  B)

  C)

  D)

  E)

  F)

  G)

  H)

  I)

  J)

  K)

  L)

  M)

  N)

  O)

  P)

  Q)

  R)

  
• Nuclear transmutation: when an atom changes into a different element
• Beta minus

  : occurs when the nuclei has too many neutrons, emitting an electron while a neutron spontaneously changes into a proton
• Beta Plus

  : when the nucleus has too many protons, spontaneously changing a proton into a neutron while emitting a positron
• Gamma Decay

  : is the release of excess energy after an initial decay
• Electronvolt (eV): the energy required for an electron to gain to travel across a potential difference of one volt
• Half-life: the time taken for 50% of the original sample to decay

  $N=$$N_o(1/2)^n$

  N= number of radioactive nuclei remaining

  No= initial number of radioactive nuclei

  n= number of elapsed half-lives
• Decay curve: predicts the decay of the sample, not individual atoms
• Activity: number of decays per second (rate of decay)

  • measured in becquerels (Bq)
• Ionizing radiation - harmful to all living things when over 2 x 10^16 Hz

  Background radiation - not a significant problem to health
• Exposure to radiation

  • high ionizing radiation is harmful to living tissue
  • energy breaks apart molecules and ionizes atoms in the body's cells
  • can lead to cancer and deformities in future generations, even death in high exposures
• Radiation effect on humans

  Chronic: occurs over a long period of time

  Acute: occurs all at once
• Immediate effects of radiation

  • lowered white blood cell count
  • nausea
  • fatigue
  • hair loss
  • skin reddening
• Prolonged radiation exposure may lead to DNA damage or create cancerous cells
• Cancer can be detected through radioactive tracers (radioisotopes that have been tagged to drugs)

  • drugs may be administered through: ingestion, inhalation or injection
  • the radioisotope used is dependent on the site of the suspected tumor, as the body naturally distributes elements to different organs
  • when the tracer reaches the target, radiation scan is done with a gamma ray camera
• Detecting cancer

  radioisotopes must be:

  • Gamma emitters - as they have enough penetrating ability to reach the detector
  • Short half-lives - ensures that the patient isn't exposed to unnecessary radiation