Question

a reference atom is needed for measuring atomic mass​

Answer 1

Answer:

Carbon-12 is the reference for all atomic mass calculations. An atomic mass unit is defined as a mass equal to one twelfth the mass of an atom of carbon-12. The mass of an atom is affected by the interactions of particles within the nucleus.

Answer 2

Answer:

Atomic mass is the sum of electron and neutron in the atoms. Atomic number gives the number of electrons So, to determine the atomic number the reference of atom is needed.