Mass Spectra

The mass spectrum of a material, deduced using a machine called a mass spectrometer, reveals how many isotopes of a given element are to be found in the material. See here what these spectra look like and how they are useful.

Mass spectrometers measure the range of possible masses for the particles making up the sample being tested. This results in a spectrum – the mass spectrum – for the substance under study. That spectrum reveals how many isotopes of a given element are to be found in the material. This is known as the isotope’s relative abundance – relative, that is, to the other isotopes found in the sample. Isotopes are atoms of the same element that have different atomic weights, due to varying numbers of neutrons (the neutrally-charged particles found in an atom's nucleus). Depending on the isotopes that make up a particular sample, researchers glean clues about its origin and how it was formed.

This tutorial shows the mass spectrum of seven different elements. Choose among them from the drop-down Menu of Elements. As you can see, gallium, for example, has two different isotopes. One of them – the one with an atomic weight of 69 – is more abundant than the other.

Last modified on 20 October 2014