It’s the The University of Nottingham’s Periodic Table of QR codes.

You may know that the UoN has made a great collection of short, vignette videos telling you something about each element on the periodic table, and this set of QR codes (that you scan with your smartphone) will take you to the You Tube clip for the element.

UoN QR Codes

UoN QR Codes

Here’s a quick clip explaining it.