What is the unit for measuring atomic mass?

The atomic mass is measured in atomic mass units (amu), which provides a standardized way to express the mass of an atom relative to the masses of other atoms. One atomic mass unit is defined as one twelfth the mass of a carbon-12 atom, which serves as a reference point. This unit is particularly useful in chemistry and physics because it allows for easy comparison of the masses of different atoms, which can vary significantly.

Using grams, kilograms, or milligrams for atomic mass would not be appropriate because these units are designed for macroscopic measurements and do not sufficiently reflect the scale of atomic and subatomic particles. Atomic mass units allow scientists to communicate and calculate atomic-scale masses more accurately and effectively, making amu the preferred unit in atomic and molecular physics.