The periodic table of elements is a familiar image for anyone who has spent time in a chemistry classroom, but despite all the information packed into those classic wall posters students today need to understand more than just the elements. This is the inspiration behind Isotopes Matter, a set of interactive educational resources from the International Union of Pure and Applied Chemistry (IUPAC). Visitors to Isotopes Matter will find a colorful interactive periodic table where clicking on each element brings up information on its isotopes, highlights a current use of that element, and links to a PDF with further isotopic information. In addition to this, Isotopes Matter also provides a set of peer-reviewed educational resources about isotop...