Mass Spectrometry and Atomic Identification (4E) Practice Test

A research group analyzes an unknown diatomic molecule by mass spectrometry. The ion source produces both $\text{M}^+$ and a fragment ion $\text{X}^+$. The spectrum contains two strong peaks: $m/z=28$ (assigned to $\text{M}^+$) and $m/z=14$ (assigned to $\text{X}^+$). Assume all detected ions are singly charged ($z=+1$). Constants: $1,\text{u}=1.66\times10^{-27},\text{kg}$.

Which conclusion about the ionization/fragmentation process is most consistent with these data?

A compound is analyzed by mass spectrometry and produces a molecular ion peak at $m/z=46$ (singly charged). The analyst repeats the experiment using a softer ionization setting that reduces fragmentation but does not change the molecular mass. The molecular ion peak remains at $m/z=46$, but fragment peaks decrease in intensity.

Which conclusion about the mass-to-charge ratio is most consistent with these results?