Question

The average atomic mass recorded on the periodic table for cobalt is 58.933 u. This indicates that the most abundant isotope of cobalt is

cobalt-57.

cobalt-58.

cobalt-59.

cobalt-60.

Answer 1

cobalt-59.

Answer 2

the most common isotope of an element is usually the one with a mass closest to the average. In this case, jagan is correct, 59 is the most likely isotope.