Which device is used for analyzing the mass of ions?

The mass spectrometer is specifically designed to analyze the mass of ions. It works by ionizing chemical species and sorting the resulting ions according to their mass-to-charge ratio. This allows for the precise determination of the mass of the ions present in a sample. During the process, ions are generated, accelerated, and then passed through a magnetic or electric field that separates them based on their mass. The data collected is used to create a mass spectrum, which helps in identifying and quantifying the substances within a sample.

Other devices listed do not serve this specific purpose. Chromatographs are primarily used for separating mixtures into their individual components rather than directly measuring mass. Molecular spectrometers analyze how molecules interact with light to provide information regarding their structure and composition, but again, they do not measure mass. Electron microscopes are utilized for imaging at very high resolutions and provide details about the surface structure of materials rather than quantifying ions based on mass. Thus, the mass spectrometer is the correct choice for analyzing the mass of ions.