Naturally occurring iodine has an atomic mass of 126.9045. A 12.3849- sample of iodine is accidentally contaminated with 1.00070 of , a synthetic radioisotope of iodine used in the treatment of certain diseases of the thyroid gland. The mass of is 128.9050 .
Find the apparent "atomic mass" of the contaminated iodine.
atomic mass= x amu