Answer: niton

AnswerCrossword Clue
NITONRadon, originally
NITONElement that shines in dark.
NITONElement now called radon.
NITONFormer name of radon.
NITONGaseous element
NITONRadioactive element
NITONInert gas
NITONRadon, formerly
NITONFormer name for radon
NITONFormer name of radon
NITONRadon formerly
NITONRadon once
niton(formerly) radon. Symbol: Nt
nitona gaseous radioactive element