Atomic structure + radiation

• What is the nucleus of an atom made up of?

  Protons and neutrons
• Whats the charge of a proton?

  Positive (+1)
• Whats the charge of a neutron?

  Neutral (0)
• Whats the size of a nucleus?

  $1\cdot10^{-14}m$
• Whats the charge of an electron?

  Negative (-1)
• Whats the size of an atom?

  $1\cdot10^{-10}m$
• What is Z in the following element mean?$_ZX$


  Atomic number, total number of protons, defines the element
• What is Y in the following element $^YX$


  Mass number, number of protons + neutrons
• What is the charge for an atom?

  None - No. protons = No. electrons
• Whats the charge of an ion?

  +/- No. protons $\ne$ No. electrons
• Whats an isotope?

  Atoms of the same element with a different number of neutrons.
• Whats the charge of alpha radiation?

  +2
• Whats the range of alpha radiation?

  A few centimetres
• Whats the charge of beta radiation?

  Negative (-1)
• Whats the range of a beta particle?

  Short - longer than alpha
• What is gamma radiation?

  High-energy electromagnetic radiation emitted during radioactive decay or nuclear reactions.
• Whats the range of gamma radiation?

  Really long, hard to stop
• How do we show alpha in terms of nuclear reaction?

  A)

  
• How do we show alpha in terms of nuclear reaction?

  .

  
• What is activity in radiation?

  What is count-rate in radiation?

  Rate at which a source of unstable nuclei decays

  The number of decays recorded each second by a detector
• Whats is the half life of a radioactive isotope?

  Time take for No. nuclei of the isotope in a sample to halve.
• Whats irradiation?

  Process of exposing an object to nuclear radiation
• What is contamination?

  The unwanted presence of material containing radioactive atoms on other material(s)
• What is nuclear fission?

  Splitting of a large and unstable nucleus.
• What is nuclear fusion?

  The joining of two light nuclei to form a heavier nucleus