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        Matter is made up of indivisible particles called atoms. - 
  
  
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        The atom was a solid ball that could not be broken down any further. - 
  
  
        The atom is made up of smaller particles that which are either positively or negatively charged. - 
  
  
        Atoms have a nucleus where positive charged protons exist. Electrons revolve around the nucleus. - 
  
  
        Electrons orbit the nucleus in levels from the nucleus outward.