The atomic mass of an element is equal to
A)its mass number.
B)its atomic number.
C)one-twelfth of the mass of a carbon-12 atom.
D)a weighted average mass of all of the naturally occurring isotopes of the element.
E)the average mass of all of the naturally occurring isotopes of the element.

Question

Quizplus · Accepted Answer

The atomic mass of an element is a weighted average mass of all of the naturally occurring isotopes of the element. This means that it takes into account not only the masses of each isotope, but also the relative abundances of each isotope in nature. This is why the atomic mass is not always a whole number, as it takes into account the contribution of each isotope.

The Atomic Mass of an Element Is Equal to