Question

question 1. explain the difference between mass number and average atomic mass.

Explanation:

Mass number is the sum of protons and neutrons in a single isotope's nucleus, a whole - number value for a specific isotope. Average atomic mass is a weighted average of the masses of all naturally - occurring isotopes of an element, taking into account their relative abundances. Since it's a weighted average based on different isotopic masses and abundances, it's often not a whole number.

Answer:

Mass number is for a single isotope (sum of protons and neutrons, whole - number), while average atomic mass is a weighted average of all isotopes' masses (usually not a whole number due to abundances).