identify the following element if it has three naturally occurring isotopes 50% of which have an atomic mass of 127 amu, 40% at 128 amu, and 10% at 129 amu

Answer 1

The element with three naturally occurring isotopes, where 50% have an atomic mass of 127 amu, 40% have an atomic mass of 128 amu, and 10% have an atomic mass of 129 amu is iodine (I).