A handy Excel spreadsheet for looking up elemental isotopes by symbol or mass.
I created this spreadsheet for fun, but also to help me quickly lookup the abundance of the various isotopes.
As a new CyTOF (Cytometry by Time of Flight) user, I learned that the CyTOF (and presumably other systems, such as mass spectrometers) can discrimate only by the mass of the element, not the specific isotope.
Thus, if you're seeing a signal of a specific mass that is unexpected, you can use this tool to lookup what it's most likely to be, both by mass and symbol.
Looking up by symbol will provide the relative isotope abundances of that element.
Looking up by mass will provide a "best guess" as to what the most likely element is, based partly on the isotopic abundance, but also on the element's abundance on earth.
Obviously, this is a "crude" tool and will almost certainly contain errors, but I find it useful and it was fun to make!