The atomic mass unit is designed with carbon-12 in mind. We discussed in class how the
mass of a carbon-12 atom is defined as exactly 12 amu. We also discussed how this helps us
determine Avogadro’s number. We can see therefore that Avogadro’s number is not
fundamental but is instead a construction which has been installed for convenience. Imagine
devising a new atomic mass unit (namu) which would define the mass of an oxygen-16 atom as
exactly 16 “namu” What would Avogadro’s number be based on this system? (The mass of an
oxygen-16 atom is 2.6560×10-23 g.)

Question

The atomic mass unit is designed with carbon-12 in mind. We discussed in class how the
mass of a carbon-12 atom is defined as exactly 12 amu. We also discussed how this helps us
determine Avogadro’s number. We can see therefore that Avogadro’s number is not
fundamental but is instead a construction which has been installed for convenience. Imagine
devising a new atomic mass unit (namu) which would define the mass of an oxygen-16 atom as
exactly 16 “namu” What would Avogadro’s number be based on this system? (The mass of an
oxygen-16 atom is 2.6560×10-23 g.)