Physics CP06 Radioactivity

• What is the purpose of a particle view in atomic physics?

  To simplify complex systems for easier understanding
• What does a particle view show in atomic physics?

  Only the important particles
• How do different elements vary in atomic structure?

  They have different numbers of particles in their atoms
• What was the key setup of Rutherford's experiment?

  • A thin gold foil was used
  • It allowed observation of particles passing through
• What was observed in Rutherford's experiment regarding alpha particles?

  Most alpha particles passed straight through, but some were deflected or bounced back
• What aspect of Rutherford's evidence is difficult to explain with simpler particles?

  The bouncing back of some particles
• What are the key atomic models and their development evidence?

  • Dalton's model: solid sphere
  • Thomson's model: plum pudding
  • Rutherford's model: nucleus with electrons
  • Evidence from experiments led to these developments
• How would you describe the Rutherford model of the atom?

  It has a small, dense nucleus with protons and neutrons, and electrons orbiting around
• What is the charge of a proton?

  Positive
• What is the charge of a neutron?

  No charge
• What is the charge of an electron?

  Negative
• What are the relative masses of protons, neutrons, and electrons?

  • Proton: 1
  • Neutron: 1
  • Electron: Very small
• What defines the atomic number of an atom?

  The number of protons in its nucleus
• What is the mass number of an atom?

  The total number of protons and neutrons in an atom
• What are isotopes?

  Atoms of the same element with different numbers of neutrons
• What is the most common isotope of carbon?

  Carbon-12
• How many protons and neutrons does Carbon-12 have?

  6 protons and 6 neutrons
• How many protons and neutrons does Carbon-14 have?

  6 protons and 8 neutrons
• What is the relative atomic mass of carbon?

  12.01
• What does the relative atomic mass represent?

  The average mass of all isotopes of an element
• What is the maximum number of electrons that can occupy a single orbital?

  2
• How many orbitals are there in a subshell with l=1?

  3
• What are the possible values of ml for an electron in a p orbital?

  • 1, 0, +1
• What is background radiation?

  Low-level radiation present everywhere from natural and human sources
• What are the main sources of background radiation?

  Natural sources and human activities
• What are the natural sources of background radiation?

  • Radioactive isotopes in rocks and soil
  • Cosmic rays from space
  • Radon gas from uranium decay
  • Radioactive isotopes in food and drink
  • Radioactive isotopes in our bodies
• What are the man-made sources of background radiation?

  • Nuclear weapons testing
  • Nuclear power stations
  • Medical procedures (e.g., X-rays)
  • Consumer products (e.g., smoke detectors)
• How is background radiation measured?

  Using a Geiger-Müller tube
• What is the unit of activity for measuring radioactivity?

  Becquerel (Bq)
• What does the count rate in a Geiger-Müller tube indicate?

  The activity of the radiation
• Why does the count rate vary with location?

  Due to different sources of background radiation
• What is the corrected count rate?

  The measured count rate minus the background count rate
• What is the half-life of a radioactive substance?

  The time it takes for half of the radioactive atoms to decay
• How can you determine the half-life from a graph?

  By finding the time it takes for the amount to halve
• Why is it important to take multiple measurements of radioactivity?

  To reduce the impact of random errors
• What is the significance of background radiation in measurements?

  It must be subtracted to get accurate values
• What are the dangers associated with radioactivity?

  • Nuclear accidents
  • Handling radioactive sources
  • Radiation exposure in hospitals
• What are some examples of radioactive decay?

  • Alpha decay
  • Beta decay
  • Gamma decay