How does the atomic number differ from the mass number? What information does each provide about an atom?
ChemistryClass 9CBSEAnswered 12 May 2026
Answer
The atomic number (Z) represents the number of protons in an atom's nucleus and uniquely identifies an element. The mass number (A) represents the total number of protons and neutrons in an atom's nucleus. The atomic number tells us the element and the number of electrons in a neutral atom, while the mass number indicates the atom's total nuclear mass.
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