The mass number of a nucleus is

A. Always less than its atomic number

B. Always more than its atomic number

C. Always equal to its atomic number

D. Sometimes more and somtimes equal to its atomic number

Answer: Option D

Solution(By Examveda Team)

The mass number (A), is the total number of protons and neutrons in an atomic nucleus so sometimes more than and sometimes equal to its atomic number, depends upon no of neutrons.