Chemist have developed a method of measuring the mass of an atom called what?

Answer: Mass Spectrometer Explanation: Using the mass spectrometry method we find the smallest atom. Even the heaviest atoms are only a hundred times heavier than this. There are different types of mass spectrometer all of which work on the same principle. There are three main parts in mass spectrometer: (1) Ion source (2) Mass analyser (3) Detector and recorder.