The atomic mass system is based upon
A) the mass of uranium-238, since it is the heaviest element occurring in nature.
B) the mass of the neutron.
C) the mass of liquid water.
D) the mass of carbon-12, a very common isotope of carbon.

Question

Quizplus · Accepted Answer

The atomic mass system is based upon the mass of carbon-12, a very common isotope of carbon. One atomic mass unit (amu) is defined as 1/12th of the mass of a carbon-12 atom. This provides a standard reference for determining the masses of all other atoms.

The Atomic Mass System Is Based Upon