Version: unknown (using 4.3.85 (KDE 4.3.85 (KDE 4.4 Beta2)), Gentoo) Compiler: x86_64-pc-linux-gnu-gcc OS: Linux (x86_64) release 2.6.32 The "Nuclear Calculator" plasmoid provides a pair of combo boxes for amount selection: 1. mass units: grams/tons/... 2. mass/moles Those 2 combo boxes don't make sense, because if you want to define the amount in moles, the mass units combo box becomes useless. (now you can re-read the Short Description ;) )