Question

what is the definition and formula of atomic mass number​

Answer 1

Answer:

Atomic mass = Number of protons + Number of neutrons + Number of electrons

Atomic mass is the total of the masses of the electrons, neutrons, and protons in an atom, or in a group of atoms, the average mass. When compared to protons or neutrons electrons have so much less mass that they don’t influence the calculation. Thus, the total of the masses of neutrons and protons is the atomic mass.

Explanation:

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Answer 2

Answer:

DEFINITION:

                  the sum of number of protons and neutrons in the nucleus of an      atom is called atomic mass or mass number. it is denoted by A

Explanation:

A=Z+n

Z=A-N

where z is the number of protons and n is the number of neutrons