Atomic structure and mass spectrometry

• how can the relative abundance values be used to calculate the relative atomic mass ?

  (relative abundance isotope 1 x mass )+(relative abundance isotope 2 x mass)etc / 100
• how can the percentage abundance of the isotope in an element be found ?

  through the use of a mass spectrometer
• what is the basic process of mass spec ?

  • The sample is vapourised
  • The sample is ionised to form positive ions
  • The ions are accelerated
  • Heavy ions move slower / are less deflected
• how are the ions detected in mass spec (what format) ?

  • The ions are detected as a mass-to-charge ratio, written as 
  • Each ion produces a signal, so the larger the signal, the greater the abundance
• what can the mass spectra also be used to find ?

  to calculate the relative atomic mass of an element and its isotopes
• what is relative molecular mass applied to ?

  Relative molecular mass is applied to chemicals that have a fixed formula in terms of the number of atoms involved
• what is relative formula mass applied to ?

  Relative formula mass is applied to chemicals that use an empirical formula to represent them
• how are you the relative molecular mass and relative formula mass both calculated ?

  by adding up the relative atomic masses of all the component atoms