Which of these statements concerning the atomic mass is correct?
A) The a tomic mass is the same as the mass number of the most common isotope.
B) The atomic mass is derived from the weight of the most common isotope of an element.
C) The atomic mass is determined by adding the masses of the protons, electrons, and neutrons in the atom.
D) The atomic mass is calculated from the atomic masses of the two most common isotopes.
E) The atomic mass is a weighted average of the masses of the naturally occurring isotopes.

Question

Quizplus · Accepted Answer

The atomic mass is a weighted average of the masses of the naturally occurring isotopes. This is because most elements have multiple isotopes with different masses, and the percentage of each isotope present in a sample of the element affects the overall atomic mass. The atomic mass on the periodic table is typically a decimal value because it reflects this weighted average.

Which of These Statements Concerning the Atomic Mass Is Correct