Can u plz tell where are the statements
Answer:precisely 1/12 the mass of an atom of carbon-12.
Explanation:The carbon-12 (C-12) atom has six protons and six neutrons in its nucleus. In imprecise terms, one AMU is the average of the proton rest mass and the neutron rest mass.
If your question is of the core of the Earth, it is suspected to be made of iron and nickel.