properties of alpha, beta and gamma radiation

• Gamma radiation can be significantly reduced by…


  lead
• What form of radiation is emitted by nuclei with too many neutrons?

  Beta
• Alpha is emitted by a nucleus with too few neutrons.
• Gamma radiation is...


  an electromagnetic wave.
• Which form of radiation has the highest ionising power?


  Alpha
• What causes an atom's nucleus to become unstable?


  Too many or too few neutrons.
• What is the activity of a source that emits 1,200 particles per minute?


  20 Bq is the activity of a source that emits 
• Uranium 238 emits an alpha particle to become what nucleus?


  Thorium-234
• An alpha particle is…


  A helium nucleus with two protons and two neutrons.
• What is meant by radioactive decay?


  It is the process by which an unstable nucleus gives out radiation to become stable.
• How many types of nuclear radiation are there?


  There are four types of nuclear radiation.
• Why do some isotopes undergo radioactive decay?


  Because they have an unstable nucleus that needs to become stable.
• What is an isotope?


  Isotopes are atoms of the same element with different numbers of neutrons.
• Which type of radiation can reach the furthest

  gamma
• What is carbon-14?


  Carbon-14 is a radioactive isotope of carbon.
• What happens during radioactive decay?


  The nucleus gives out radiation to become stable.
• What is the definition of activity in the context of radioactive decay?


  Activity is the rate at which a source of unstable nuclei decay.
• How is activity measured?

  Activity is measured in Becquerels (Bq).
• What does one Becquerel (Bq) represent?

  One Bq equals one decay per second.
• What is a Geiger-Müller tube used for?

  It is used to measure the activity of a radioactive source.
• What is the count rate in the context of radioactivity?

  The count rate is the number of decays recorded each second by a detector.
• How does count rate differ from activity?


  Count rate is affected by background radiation, while activity is the actual decay rate.
• What is an alpha particle composed of?


  An alpha particle consists of two protons and two neutrons.
• What is the relationship between an alpha particle and a helium atom?


  An alpha particle is the same as the nucleus of a helium atom.
• What is a beta particle?


  A beta particle is an electron ejected from the nucleus at high speed.
• How is a beta particle formed?


  A beta particle is formed when a neutron changes into a proton and an electron inside the nucleus.
• What is a gamma ray?


  A gamma ray is a type of electromagnetic radiation emitted from the nucleus.
• What is the fourth type of radiation that can be emitted by an unstable nucleus?

  The fourth type of radiation is a neutron.
• What are the four types of nuclear radiation?

  • Alpha particles: Consist of two protons and two neutrons.
  • Beta particles: Electrons ejected from the nucleus.
  • Gamma rays: Electromagnetic radiation from the nucleus.
  • Neutrons: Sometimes emitted by unstable nuclei.
• What fraction of a radioisotope has decayed after two half-lives? -


  Three quarters of a radioisotope has decayed after two half-lives. 
• What is the range of alpha particles in air?


  About 5 centimeters
• How far can beta particles travel in air before stopping?


  About 15 centimeters
• What is the range of gamma radiation in air?


  Several meters
• What does penetrating power indicate about radiation?


  It indicates what type of material is required to stop each form of radiation
• What material can stop alpha particles?


  A single sheet of paper
• What is required to stop beta particles?


  A few millimeters of aluminum
• What material is needed to stop gamma radiation?


  Several centimeters of lead
• What does ionizing power refer to in the context of radiation?


  It refers to the ability of radiation to cause atoms to lose electrons and form ions
• How strongly ionizing are alpha particles?


  Very strongly ionizing
• How does the ionizing power of beta particles compare to alpha particles?


  Beta particles are quite strongly ionizing but not as ionizing as alpha particles