Mass spectrometry of elements Transitional Reasoning Download PDF

Questions

1. 1.

   In a mass spectrometer, a gaseous sample of an unknown element is ionized to produce singly charged cations ($+1$) and accelerated through an electric field before being separated by a magnetic field. The resulting mass spectrum reveals two distinct peaks at $m/z = 63$ and $m/z = 65$ with a relative intensity ratio of $3:1$, respectively. Based on these mass spectrometry data, which statement correctly identifies the relative atomic mass of the element and the structural relationship between the detected species?

   • A) The relative atomic mass is 63.5, and the peak at $m/z = 65$ corresponds to an isotope containing two more neutrons than the isotope at $m/z = 63$.
   • B) The relative atomic mass is 64.0, and the peak at $m/z = 65$ represents an ion that retained two extra electrons during the ionization stage.
   • C) The relative atomic mass is 63.5, and the peak at $m/z = 65$ represents an ion that was deflected more strongly by the magnetic field than the lighter ion.
   • D) The relative atomic mass is 64.5, and the peak at $m/z = 63$ represents a species containing two fewer nuclear protons than the isotope at $m/z = 65$.