Question

What is meant by atomic mass number?
Explain how the atomic number of carbon are 6 and 12 respectively??

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Answer 1

1.Atomic number and mass number are always whole numbers because they are obtained by counting whole objects (protons, neutrons, and electrons). The sum of the mass number and the atomic number for an atom (A-Z) corresponds to the total number of subatomic particles present in the atom. The mass number reports the mass of the atom’s nucleus in atomic mass units (amu)

2.Since the mass of electrons are negligible, the mass of an element is often taken as the sum of number of protons and neutrons. ... Carbon has 6 protons, 6 electrons and 6 neutrons. So the atomic number is 6 as the number of protons is 6. The mass number is 12 as the sum of protons and neutrons is 12