Radioactive decay

• What defines an element in terms of protons?

  An element is defined by a fixed number of protons in its atoms.
• What are isotopes?

  Isotopes are nuclei that have the same number of protons but different numbers of neutrons.

  
• How many isotopes does hydrogen have?

  Hydrogen has two isotopes: deuterium and tritium.

  
• What is the nucleon number A in relation to isotopes?

  The nucleon number A includes the number of protons and neutrons in an isotope.

  
• What happens to unstable isotopes?

  Unstable isotopes constantly decay and emit radiation to achieve a more stable form.
• What is isotopic data?

  Isotopic data is the relative amounts of different isotopes of an element present within a substance.
• How is the relative atomic mass of an element displayed on the periodic table?

  The relative atomic mass takes into account the masses and abundances of all naturally occurring isotopes of an element.
• How can the percentage abundance of different isotopes in a sample be obtained?

  The percentage abundance can be obtained using a mass spectrometer.
• How is the relative atomic mass of a sample of oxygen calculated?

  The relative atomic mass can be calculated using the formula: $(16 \times 0.9976) +$$(17 \times 0.0004) +$$(18 \times 0.002) =$$16.0044$.
• What is a common use of isotopic data?

  A common use of isotopic data is carbon dating of archaeological artifacts.
• How does carbon dating work?

  Carbon dating involves using the ratio of stable isotope carbon-12 to unstable isotope carbon-14 to determine the age of a sample.
• What is the definition of radioactive decay?

  Radioactive decay is the spontaneous disintegration of a nucleus to form a more stable nucleus, resulting in the emission of an alpha, beta, or gamma particle.
• How can the randomness of radioactive decay be demonstrated?

  The randomness of radioactive decay can be demonstrated by observing the count rate of a Geiger-Muller tube, which shows irregular counts that cannot be predicted.
• What is a spontaneous process in the context of radioactive decay?


  A spontaneous process is one that cannot be influenced by environmental factors such as temperature, pressure, or chemical conditions.
• What is a random process in the context of radioactive decay?

  A random process is one in which the exact time of decay of a nucleus cannot be predicted, but the probability of decay remains constant over time.
• What is background radiation?

  Background radiation is the ionizing radiation present in the environment.
• What are the two main sources of background radiation?

  The two main sources of background radiation are natural sources and artificial sources.
• What is the largest proportion of background radiation in the UK?

  In the UK, radon gas is by far the largest proportion of background radiation.

  
• What is the danger of inhaling radon gas?

  Inhaling radon gas in large quantities can be particularly dangerous as it is an alpha emitter.
• How can radon gas be detected?

  Radon gas can only be detected using a Geiger counter.
• What are cosmic rays and their sources?

  Cosmic rays are subatomic particles emitted by the Sun and other high-energy cosmic events, such as supernovae.
• What is the significance of carbon-14 in biological material?

  All organic matter contains a tiny amount of carbon-14, which remains constant in living organisms.
• How can radioactive material enter food and drink?

  Radioactive material can enter food and drink through contact with rocks and soil containing naturally occurring radioactive elements.
• What are some artificial sources of background radiation?

  Artificial sources of background radiation include nuclear medicine, nuclear waste, and nuclear fallout from weapons.
• What is nuclear fallout?

  Nuclear fallout is the residue radioactive material thrown into the air after a nuclear explosion.
• What is the impact of nuclear accidents on background radiation?

  Nuclear accidents contribute a large dose of radiation to the environment and can have long-lasting effects.
• How should background radiation be accounted for in laboratory readings?

  Background radiation should be accounted for by taking readings with no radioactive source present and subtracting this from readings with the source present.
• How can the background count rate be measured?

  The background count rate can be measured using a Geiger-Muller tube with no source present.

  
• How is the corrected count rate determined?

  The corrected count rate is determined by measuring the count rate of a source and subtracting the background count rate.
• If a Geiger counter records 285 counts in 1 minute with a source present and 24 counts in 1 minute without, what is the corrected count rate?

  The corrected count rate is $261 \text{ counts per minute (cpm)}$.
• How can the accuracy of count rate measurements be improved?

  The accuracy can be improved by repeating readings and taking averages, and taking readings over a long period of time.
• What are the three main types of radioactive particles or radiation?

  The three main types are alpha particles, beta particles, and gamma radiation.
• What is an alpha particle?

  An alpha particle is a high-energy helium nucleus containing 2 protons and 2 neutrons.
• What is the mass and charge of an alpha particle?

  An alpha particle has a mass of 4u and a charge of +2e.
• What happens to a nucleus when an alpha particle is emitted?

  When an alpha particle is emitted, the nucleus loses 2 protons and 4 nucleons, resulting in a different element.

  
• How does the emission of an alpha particle affect the parent and daughter nuclei?

  The parent nucleus becomes a different element than the daughter nucleus after emitting an alpha particle.

  
• What process allows a nucleus to become more stable by emitting particles or radiation?

  Radioactive decay

  
• What are the three main types of radioactive particles or radiation?

  • Alpha particles
  • Beta particles
  • Gamma radiation

  
• What is an alpha particle?

  An alpha particle is a high-energy helium nucleus
• How many protons and neutrons does an alpha particle contain?

  2 protons and 2 neutrons