A series of collaborative learning activities and accompanying text that develop fundamental aspects of mass spectrometry. These activities are intended to be done in class by students working in groups, but can be modified for use as out-of-class exercises. Learning objectives are provided as well. In addition to some basic concepts of mass spectrometry, the importance of fragmentation patterns and isotopes in spectral interpretation is developed. The use of delta values for isotopic abundance and how delta values can be used to distinguish C3 and C4 plants is developed. The final activity involves the analysis of a literature article that uses mass spectrometry to determine the extent of C3 and C4 plants in the North American diet.