Final answer:
The new unit for atomic or molecular weight is the unified atomic mass unit (u), which is more convenient than kilograms on the atomic and nuclear scale. It is defined as one-twelfth of the mass of one atom of carbon-12.
Step-by-step explanation:
The new unit for atomic or molecular weight to be used in all future outcomes and lessons is the unified atomic mass unit (u). This unit is more convenient than kilograms on the atomic and nuclear scale because individual atoms and molecules are very small and their masses are also very small. The unified atomic mass unit (u) is defined as one-twelfth of the mass of one atom of carbon-12, which experiments have shown to be equal to 1.66 x 10-24 grams.
The atomic mass unit (u) describes the masses of individual atoms and molecules, while the atomic mass is the weighted average of the masses of all isotopes of an element. The molecular mass is the sum of the masses of the atoms in a molecule.