krypton
From Glossary of Meteorology
(Symbol Kr.) An inert element, fourth member of the noble gas family, atomic number 36, atomic weight 83.7; an element found in the atmosphere to the extent of only 0.000114% by volume.
(Symbol Kr.) An inert element, fourth member of the noble gas family, atomic number 36, atomic weight 83.7; an element found in the atmosphere to the extent of only 0.000114% by volume.