Question

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Answer 1

Answer:

A.M.U

Explanation:

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Answer 2

Answer:

A relative atomic mass (also called atomic weight; symbol: Ar) is a measure of how heavy atoms are. It is the ratio of the average mass per atom of an element from a given sample to 1/12 the mass of a carbon-12 atom. ... An atom of an element with a certain number of neutrons is called an isotope.