"Weighing" atoms with electrons

uni:view magazin Videos Presse Social Media - 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. Publishing in the prestigious open access journal "Nature ", researchers at the University of Vienna report a new way for "weighing" atoms by atomic-resolution imaging of graphene, the one-atom-thick sheet of carbon. The different elements found in nature each have their distinct isotopes. For carbon, there are 99 atoms of the lighter stable carbon isotope ¹²C for each ¹³C atom, which has one more neutron in its nucleus. Apart from this natural variation, materials can be grown from isotope-enriched chemicals.