Radioactivity

• What are the two ways of detecting radiation?

  • using photographic film
  • using a Geiger - Muller tube
• How do we know that radiation is present using photographic film?

  The photographic film becomes foggy. The darker the photographic film, the more radiation.
• What are the sources of background radiation?

  • ground and buildings
  • medical
  • radon and thoron gas which are products formed from the decay of radioactive materials.
  • cosmic rays which come from nuclear reactions in stars, supernovae, the sun.
  • food and drinks which contain radioactive isotopes
  • leaking of radioactive material into the environment
• What is radioactive decay?

  Radioactive decay is a random process. It is the number of decays that occur per unit time. it is measured in Becquerels.
• What is the unit for activity (radioactive decay) ?

  Becquerels.
• What is half life?

  It is the length of time it takes for the activity of an amount of radioactive substance to halve.
• What are atoms made up of?

  Protons, neutrons and electrons.
• What is atomic number?

  It is the total number of protons in the nucleus of an atom.
• What is atomic mass?

  It is the total number of protons and neutrons in the nucleus of an atom.
• What are isotopes?


  Atoms of the same element with the same number of protons but a different number of neutrons.
• Protons are held in the nucleus by which kind of force?

  Nuclear force.
• The force that causes protons to repel one another because they have the same charge is called?

  Electric force.
• what are the three types of ionising radiation?

  Alpha , beta , gamma.
• What type of radiation is the most ionising?

  Alpha radiation.
• What type of radiation is the most penetrating?

  Gamma radiation.
• What does range mean?

  It is the distance that ionising radiation can travel through matter
• One becquerel is equal to?

  One decay per second.