What does a mass spectrometer measure?

What does a mass spectrometer measure?

• A. Atomic number
• B. Ionization energy
• C. Mass-to-charge ratio of ions
• D. Flame color

Answer: (C)

Mass spectrometry measures the mass-to-charge ratio of ions. In this technique, the sample is ionized to create charged particles, which are then accelerated and passed through electric and magnetic fields so ions with different mass-to-charge ratios separate along different paths. A detector records the abundance of ions at each m/z value, producing a spectrum. From the peaks, you can determine the molecular weight (especially for singly charged ions) and gain information about isotopes and composition. The mass-to-charge ratio is the fundamental quantity revealed by the instrument, which is why this choice is correct. Atomic number is a property of the element's nucleus and isn’t directly measured by mass spectrometry. Ionization energy is the energy required to remove an electron, not a measurement the instrument reports. Flame color comes from electronic transitions in a flame, not from separating ions by mass-to-charge ratio.

Mass spectrometry measures the mass-to-charge ratio of ions. In this technique, the sample is ionized to create charged particles, which are then accelerated and passed through electric and magnetic fields so ions with different mass-to-charge ratios separate along different paths. A detector records the abundance of ions at each m/z value, producing a spectrum. From the peaks, you can determine the molecular weight (especially for singly charged ions) and gain information about isotopes and composition. The mass-to-charge ratio is the fundamental quantity revealed by the instrument, which is why this choice is correct.

Atomic number is a property of the element's nucleus and isn’t directly measured by mass spectrometry. Ionization energy is the energy required to remove an electron, not a measurement the instrument reports. Flame color comes from electronic transitions in a flame, not from separating ions by mass-to-charge ratio.