Answer: 207.2
Explanation:
In imprecise terms, one AMU is the average of the proton rest mass and the neutron rest mass. This is approximately 1.67377 x 10 -27 kilogram (kg), or 1.67377 x 10 -24 gram (g). The mass of an atom in AMU is roughly equal to the sum of the number of protons and neutrons in the nucleus.
Yo sup??
The answer to your question is option c ie
c.9
the rest 12 are under non essential as they are produced by our body itself
Hope this helps.
The one that starts with c that is also the one that is anwser number c which is a