radon ardon rdaon draon adron daron raodn arodn roadn oradn aordn oardn rdoan droan rodan ordan doran odran adorn daorn aodrn oadrn doarn odarn radno ardno rdano drano adrno darno rando arndo rnado nrado anrdo nardo rdnao drnao rndao nrdao dnrao ndrao adnro danro andro nadro dnaro ndaro raond arond roand orand aornd oarnd ranod arnod rnaod nraod anrod narod ronad ornad rnoad nroad onrad norad aonrd oanrd anord naord onard noard rdona drona rodna ordna dorna odrna rdnoa drnoa rndoa nrdoa dnroa ndroa ronda ornda rnoda nroda onrda norda donra odnra dnora ndora ondra nodra adonr daonr aodnr oadnr doanr odanr adnor danor andor nador dnaor ndaor aondr oandr anodr naodr onadr noadr donar odnar dnoar ndoar ondar nodar
Note: these 'words' (valid or invalid) are all the permutations of the word radon. These words are obtained by scrambling the letters in radon.