Which statement about mass number is correct?
It is always greater than atomic number
The atomic number (Z) equals the number of protons in the nucleus, while the mass number (A) equals the number of protons plus the number of neutrons.
Since every naturally occurring atom (except protium, 1H) contains at least one neutron along with its protons, A is always greater than Z; even for protium, A = Z = 1, so A is never less than Z.
Hence, the mass number is always greater than the atomic number for the atoms considered here.
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