This ductile, nonradioactive element has an atomic weight of 26.98
[DOC] [TLE] The p-Block Elements - 2012 Book Archive [PAR] All group 13 elements have ns 2np 1 valence electron configurations, and all 
tend to ... atomic mass (amu), 10.81, 26.98, 69.72, 114.82, 204.38 ...... and 
bismuthall have a metallic luster, but they are brittle (not ductile) and ...... Iodine 
is the least abundant of the nonradioactive halogens, and it is a relatively rare 
element.