No room is left at the bottom. A team of physicists has shown how a common type of electron microscope can spot single hydrogen atoms — the smallest atoms of them all.
Previously, electron microscopes had trouble imaging single atoms lighter than carbon.
The University of California, Berkeley team visualized defects and impurities — including atoms of hydrogen— on graphene, the one-atom-thick, chicken-wire nets of carbon that normally stack up to form graphite. “Think of it sort of as a spider web,” says study coauthor Alex Zettl of the graphene, “and the atoms you want to view are flies on the spider web.”