The mass number of a nucleus is,

Options

A. Always less thun alomic number
B. Always more than atomic number
C. Equal to atomic number
D. Sometimes more than and sometimes equal to atomic number

Answer

D

Explanation

Mass number = Number of protons + number of neutrons
Atomic number = Number of protons
Mass number is greater than the atomic number except,for Hydrogen Mass number and Atomic number are equal.