Topic 4

• What are the two main types of radiation mentioned?

  Man-made and cosmic rays
• What can change the arrangement of nuclear radiation?

  Absorption or emission of EM radiation
• What are the three types of nuclear radiation?

  Alpha, beta, and gamma
• How penetrating is gamma radiation?

  Very penetrating, stopped by a few cm of lead
• What is emitted when a neutron turns into a proton?

  High-speed electron
• What is the composition of an alpha particle?

  2 neutrons and 2 protons
• What are the basic atomic models mentioned?

  • Bohr Model
  • Plum Pudding Model
• What does the mass number represent?

  Number of protons and neutrons
• What determines how many electrons an atom has?

  Atomic number
• What charge do protons have?

  Positive charge
• What charge do electrons have?

  Negative charge
• What does the nucleus of an atom contain?

  Protons and neutrons
• What does the Plum Pudding Model suggest about atomic structure?

  • Atom is mostly empty space
  • Ball of positive charge
  • Negative charges scattered throughout
• What does the Bohr Model depict about electrons?

  • Central nucleus
  • Electrons in energy levels orbiting it
• What is nuclear fission?

  Splitting of large unstable nuclei
• What is nuclear fusion?

  Joining of two light nuclei into a larger nucleus
• What is a use of nuclear radiation in medicine?

  Destroying unwanted tissue
• How do medical tracers work?

  Consumed and target a part of the body
• What is the half-life of a radioactive substance?

  Time for unstable nuclei to halve
• How is radioactive decay measured?

  Using a Geiger-Muller tube
• What is the unit of activity for radioactive decay?

  Becquerels (Bq)
• What does the term 'random' refer to in radioactive decay?

  Unpredictable decay of nuclei
• What happens during radioactive decay?

  Mass is converted into energy as radiation
• What is the count-rate in radioactive decay?

  Rate at which nuclei decay
• What is the significance of short half-lives in medical tracers?

  They minimize radiation exposure
• What is the role of neutrons in nuclear fission?

  Induce further fission once released
• What is the result of nuclear fission?

  Produces two smaller nuclei and releases energy
• What happens to unstable nuclei during fission?

  Must absorb a slow-moving neutron
• How does radioactive decay relate to the concept of half-life?

  Half-life measures time for decay to halve
• What is the significance of the term 'random' in radioactive decay?

  Indicates unpredictability of decay events
• What is the purpose of gamma rays in medical applications?

  Kill unwanted cells in the body
• How do gamma rays target specific areas in the body?

  Focused onto areas to kill cells
• What is the role of radioactive tracers in medicine?

  Detect radiation in targeted body parts
• What is the relationship between mass and energy in nuclear reactions?

  Mass is converted into energy as radiation
• How does the concept of half-life apply to radioactive isotopes?

  Indicates time for half of isotopes to decay
• What is the significance of measuring radioactive decay in becquerels?

  Indicates activity of radioactive material
• What is the primary characteristic of radioactive decay?

  Unpredictable nature of decay events
• How is the count-rate of radioactive decay measured?

  Using a Geiger-Muller tube
• What is the relationship between nuclear fission and energy release?

  Fission releases energy by splitting nuclei
• What is the effect of nuclear fusion on mass?

  Mass is converted into energy