Discovered by Sir William Ramsay and M. W. Travers at
London, UK.
Remarks
Colorless, odorless gas present in the
atmosphere. Chemically inert to everything but
fluorine. 86Kr has an orange-red line in its atomic spectrum that is used
for the SI length standard where 1 meter = 1,650,763.73 wavelengths. One
meter was originally defined as 1 millionth the distance from the earth's
pole to the equator.
References
Emsley, J., 1991; THE ELEMENTS : Sec. Ed.,
Clarendon Press, Oxford, 251 p.