6.2.1 Alpha, beta, and gamma radiation

• What are beta particles?

  Electrons with -1 charge
• How does gamma radiation differ from alpha and beta radiation?

  Gamma rays have no mass and no charge
• What is the charge of beta radiation?

  -1 for electrons, +1 for positrons
• What are the key differences between alpha and beta radiation?

  • Composition:
  • Alpha: Helium nuclei
  • Beta: Electrons or positrons
  • Charge:
  • Alpha: +2
  • Beta: -1 or +1
  • Speed:
  • Alpha: Slower
  • Beta: Faster
• What is the charge of an alpha particle?

  2 protons
• At what speed do gamma rays travel?

  Speed of light
• How easily do alpha particles stop?

  They stop easily behind paper
• What is the range in air of different types of radiation?

  • Alpha: Few cm
  • Beta: Few 10s of cm
  • Gamma: Infinite
• How are different types of radiation stopped or absorbed?

  • Alpha: Stopped by few mm Aluminium
  • Beta: Stopped by few mm Lead
  • Gamma: Reduced by few mm Lead
• What is alpha radiation composed of?

  Helium nuclei
• How does the penetration ability of alpha, beta and gamma radiation differ?

  Alpha has the least penetration, gamma has the most
• What are gamma rays?

  Neutral electromagnetic waves
• What is beta radiation composed of?

  High-speed electrons or positrons
• How do the different penetrating powers of the three types of radiation relate to their physical properties?

  Alpha particles are heavy and have a high charge, so they have the lowest penetrating power. Gamma rays are high-energy electromagnetic waves with no charge or mass, so they have the highest penetrating power.
• What happens when uranium undergoes alpha decay?

  It emits an alpha particle and transforms into thorium
• How does carbon-14 decay into nitrogen-14?

  By emitting an electron
• What are the key characteristics of alpha radiation?

  • Composed of helium nuclei
  • Contains 2 protons and 2 neutrons
  • Has a positive charge of +2
  • Relatively heavy particles
• How does the penetrating power of the three types of radiation differ?

  • Gamma rays have the highest penetrating power, able to pass through thick materials like concrete
  • Beta particles have moderate penetrating power, able to pass through paper
  • Alpha particles have the lowest penetrating power, stopped by a thin layer of paper
• What does the penetrating power of radiation determine?

  How deeply they can pass through materials
• What materials are shown to have different levels of penetrating power for the three types of radiation?

  • Radioactive source
  • Paper
  • Aluminum
  • Concrete
• What is the charge of an alpha particle?

  +2
• What are the three types of radiation shown in the image?

  Gamma ray, ray of beta particles, ray of alpha particles
• How many protons are in an alpha particle?

  2 protons
• What is gamma radiation composed of?

  High-energy photons
• Why are gamma rays considered the most penetrating type of radiation?

  They can travel through inches of lead
• Compare the properties of alpha, beta, and gamma radiation.

  • Alpha Radiation:
  • Composition: Helium nuclei
  • Charge: +2
  • Speed: Slow
  • Beta Radiation:
  • Composition: Electrons or positrons
  • Charge: -1 or +1
  • Speed: Faster
  • Gamma Radiation:
  • Composition: High-energy photons
  • Charge: 0
  • Speed: Speed of light
• What is the order of penetrating power for types of radiation?

  • Alpha radiation: stopped by paper
  • Beta radiation: stopped by aluminum
  • Gamma rays: penetrate through concrete, require lead shielding
• How do beta particles compare to alpha particles in terms of weight?

  Beta particles are lighter than alpha particles
• How far can beta particles travel before being stopped?

  They are stopped by aluminum
• What are the health effects of beta radiation?

  • External: Skin penetration
  • Internal: Organ damage
• How do the wave patterns shown for each material differ?

  • Paper has a smooth, continuous wave pattern
  • Aluminium has a more irregular, wavy pattern
  • Lead has a more pronounced, jagged wave pattern
• If you wanted to shield yourself from a radioactive source, which type of radiation would you be most concerned about and what material would you use?

  Alpha radiation, shielded by a thin layer of paper
• What is the range of gamma rays?

  They have infinite range
• What protection is needed against beta radiation?

  Aluminum shielding, distance
• What is the level of ionisation for alpha, beta and gamma radiation?

  High, Medium, Low
• How does external exposure to radiation occur?

  Radiation hits from outside the body
• What type of radiation has the lowest ionization power?

  Beta
• How does the ionizing power of alpha radiation compare to gamma radiation?

  • Alpha radiation has high ionizing power
  • Due to heavy charge (+2) and energy
  • Gamma radiation has low ionizing power
  • Because it is neutral and less interactive
• What material can stop gamma rays?

  They are stopped by lead
• What is ionization in the context of radiation?

  Transfer of energy knocking off electrons