Midterm

• An atom is composed of electrons (e-), negatively charged particle, positively charged nucleus at the center, it is subdivided into two subatomic particles or nucleons called neutrons and protons

  
• The mass of N is approx. equal to the mass of Z and e-

  
• The number of e- in a stable atom is proportional to the number of Z

  
• In order for an atom to be stable and electrically neutral, the number of electrons should be proportional to the number of protons inside the nucleus

  
• Atomic shells


  Paths where electrons orbit around the nucleus

  
• Atomic shells


  • K-shell (n=1)
  • L
  • M
  • N
• Pauli Exclusion Principle Formula


  Dictates the maximum number of e- in n
• Atomic mass A


  Sum of N and Z in the nucleus

  
• The characteristic of an atom is determined by the number of neutrons and protons it contains

  
• Nuclide/Element


  The number of protons inside the nucleus determines the nuclide/element

  
• Determining the radius of a nuclide


  Use the formula: R = Ro * A^(1/3)

  
• Actual atomic mass


  Gives the accurate mass of the nucleus, which also accounts for the energy that binds the nucleons together

  
• Stable Nuclides are located in the line of stability (Black Squares)

  
• Above and below the line of stability are unstable nuclei which either have more protons (above) or more neutrons (below)

  
• ₈₃Bi209 is the upper mass limit to the line of stability. Nuclei beyond this point is most likely unstable and will undergo radioactive decay
• Isotopes


  Variation of an atom of an element which has the same number of Z; Number of N and A varies
• Isotones


  Variation of an atom of an element which has the same number of N; Number of Z and A varies
• Isobars


  Variation of an atom of an element which has an identical number of A; Number of Z and N varies
• 4 forces that govern the universe

  • Gravity
  • Electromagnetic Force
  • Strong nuclear force
  • Weak nuclear force
• Electromagnetic Force


  Keeps the electrons in orbit with the nucleus

  
• Strong nuclear force (nuclear binding force)


  Binds the nucleons together preventing them to repel
• Weak Nuclear Force


  Enables the transformation of protons to neutrons or neutrons to protons
• Electron Binding Energy


  Energy required to completely remove an electron from an atom or its shell
• Binding energy is greatest in the inner shell (k-shell) because it is nearer to the nucleus
• Binding energy increases as Z increases because the law of attraction is greater with heavier nuclide
• Nuclear Binding Energy


  Energy required to separate protons and neutrons inside the nucleus

  
• Solution


  1. Using binding energy formula

  2. Solving for actual mass

  3. Solving for binding energy
• Binding energy


  Energy required to hold the nucleus of an atom together

  
• Radiation


  Energy in transit or energy release
• Two forms of radiation in nuclear medicine

  • Particulate radiation
  • Electromagnetic radiation
• Particulate radiation


  Consists of atomic or subatomic particles that are traveling and carries energy
• Electromagnetic radiation


  Energy is carried by oscillating electrical and magnetic field traveling through space
• Electromagnetic radiation


  • Gamma rays
  • X-rays
  • Radio waves
• Radioactive decay


  Process in which an unstable nuclide transforms into a more stable element by emitting radiation
• Radioactive isotopes


  Unstable nuclides with too many protons or neutrons in the nucleus
• Parent nuclide


  The nuclide before undergoing radioactive decay process
• Daughter nuclide


  The nuclide it transforms into after the decay process
• Radioactive decay notation


  Represents the process a certain nuclei went through

  
• 5 types of radioactive decay

  • Alpha decay
  • Beta - decay
  • Positron or Beta + decay
  • Electron capture emission
  • Spontaneous fission
• Alpha decay


  Emission of two protons and two neutrons (Helium nucleus)