what is the atomic mass for iodine]
Best Answer: There is only one naturally occurring isotope of iodine, that with a mass of 126.90447 amu. If combined with a second isotope of iodine, you would find the weighted average atomic weight of the mixture this way: (12.3849 g x 126.9045 amu + 1.00070 g x 128.9050 amu) / 13.3856 g= 127.0541 amu. Source(s):