Subject: Lecture 9/12 Extra Credit (from 2001)

By using a compound's empirical formula, one can go on to analyze the properties of its individual elements including the percentage each composes of the compound and its molecular mass. The mass spectrometer most accurately determines atomic and molecular masses however. It operates by forming a beam of cations from the gaseous sample inserted into it and then guiding this beam with a magnet into a circular path. The ions are there divided according to their charge to mass ratio and then led to a detector that analyzes this data. Due to the theory of mass conservation, chemical reactions must be balanced accordingly; the least abundant element will be the limiting reagent that determines the resulting products.