Summary:
- The current system of measurement in the Unites States is a hodge-podge of different units, many of which are hard to interconvert.
- Scientists decided on using the carbon-12 nuclide as the reference standard by which all other masses would be compared.
- An atom of oxygen-16, for example, has a mass of 2.66 × 10-23 g. The mass of an atom is affected very slightly by the interactions of the various particles within the nucleus.