This is amazing.

My PhD research is actually on characterizing chemistry at the atomic scale, and it is hard to do! I’m using an electron signal rather than an x-ray signal, but still. It would be hard to overstate what an incredible technical accomplishment this is.

Of course harder problems remain: this atom was relatively isolated, and it will be much harder to get chemical signatures from single atoms embedded in, say, a crystal, but it’s great progress. (We actually can get single-atom chemical information from atoms in a crystal, using a technique called atom-probe tomography. The catch is that it’s a destructive analysis method, and I hear it’s also a pretty tricky technique to perform.)