The chemical properties of atoms depend on the number of protons in their nuclei, placing them into the periodic table. However, even chemically identical atoms can have different masses – these variants are called isotopes. Although techniques to measure such mass differences exist, these have either not revealed where they are in a sample, or have required dedicated instrumentation and laborious sample preparation. Researchers now report a new way for "weighing" atoms by atomic-resolution imaging of graphene, the one-atom-thick sheet of carbon.
from Geochemistry News -- ScienceDaily http://ift.tt/2dOFdOz