(a) What is the mass in u of a carbon-12 atom?

Verified step by step guidance

1. Understand that the atomic mass unit (u) is defined based on the carbon-12 isotope. By definition, one carbon-12 atom has a mass of exactly 12 atomic mass units (u).
2. Recall that the atomic mass unit is a standard unit of mass that quantifies mass on an atomic or molecular scale (1 u is approximately equal to 1.66053906660 x 10^-27 kg).
3. Recognize that the mass of a carbon-12 atom is used as a reference point for the atomic mass unit, meaning it is exactly 12 u by definition.
4. Consider that this definition is crucial for understanding atomic masses of other elements, as they are measured relative to the carbon-12 standard.
5. Conclude that the mass of a carbon-12 atom is exactly 12 u, which is a fundamental concept in chemistry for determining the relative atomic masses of other elements.