KA 4: Nuclear Chemistry

• What is ionisation in terms of atoms?

  Loss or gain of an electron
• What causes ionisation in atoms?

  Ionising radiation makes contact with atoms
• What device detects ionising radiation?

  Geiger-Muller tube
• What can ionising radiation damage in living organisms?

  DNA, causing burns and cancers
• What are the three types of radiation?

  • Alpha particles
  • Beta particles
  • Gamma waves
• What is an alpha particle composed of?

  Two protons and two neutrons
• What is the charge of an alpha particle?

  2+
• How ionising are alpha particles compared to other types?

  They are the most ionising
• What can block alpha particles?

  Just paper
• What is a beta particle?

  A fast-moving electron
• What is the charge of a beta particle?

  1-
• What is the mass of a beta particle?

  0
• How do gamma waves travel compared to alpha and beta particles?

  At the speed of light
• How ionising are gamma waves?

  They are the least ionising
• What are the ionising and penetration potentials of alpha, beta, and gamma radiation?

  • Alpha: Least penetrative, most ionising
  • Beta: Second most penetrative, second most ionising
  • Gamma: Most penetrative, least ionising
• What happens to atomic and mass numbers when an alpha particle is emitted?

  Atomic number decreases by 2, mass by 4
• What occurs during beta particle emission?

  A neutron splits into a proton and an electron
• What happens to the atomic number during beta emission?

  Increases by 1
• What is half-life in radioactive substances?

  Time for activity to reduce by half
• If a substance has a half-life of 3 years, when will its activity be halved?

  In 3 years
• What are the uses of radiation?

  • Energy production
  • Medical imaging (X-rays)
  • Radiotherapy for cancer
  • Sterilisation of surgical equipment
  • Carbon-dating in archaeology
  • Smoke detectors
• What is the role of X-rays in medicine?

  Imaging and diagnosing patients
• How is gamma radiation used in medicine?

  In radiotherapy for certain cancers
• What is carbon-dating used for?

  Determining ages of carbon-based compounds
• How does knowledge of radiation benefit archaeology?

  It helps determine the ages of compounds
• What is the speed of gamma waves?

  $3 \times 10^8 \text{ m/s}$
• What is the significance of practicing half-life problems?

  They are common in exams
• What are the key points about ionising radiation?

  • Ionising radiation causes ionisation
  • Can damage DNA, causing burns and cancers
  • Detected by Geiger-Muller tube
• What are the key points about types of radiation?

  • Alpha: Most ionising, least penetrative
  • Beta: Second most ionising, second most penetrative
  • Gamma: Least ionising, most penetrative
• What are the key points about nuclear equations?

  • Alpha emission: Atomic number -2, mass -4
  • Beta emission: Atomic number +1, mass unchanged
• What are the key points about half-life?

  • Activity decreases over time
  • Specific time for halving activity
  • Important for problem-solving in exams
• What are the key points about radiation uses?

  • Medical imaging and therapy
  • Energy production
  • Archaeological dating
  • Smoke detectors