ISSN 2398-2942      

Radiography: basic physics


The atom

  • All chemical elements are made of atoms.
  • Atoms consist of a core (nucleus) of protonswhich are positively charged surrounded by a cloud of electronswith a negative charge.
  • Normally there are the same number of electrons as protons in the atom so that it has no charge overall.
  • Anionis an atom that has lost or gained electrons giving it an overall positive or negative charge respectively.
  • The electrons circle the nucleus in pre-determined orbits (shells).
  • Each shell contains a pre-set number of electrons and each shell can be defined by its energy level.
  • Electrons can move from inner orbits to outer ones but moving between shells requires energy.
  • This energy can be released if the electron moves back to an inner shell.


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Further Reading


Refereed papers

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