What is the mass number of an element?
A. Mass number is the number of protons in the nucleus.
B. Mass number is the mass of the protons in the nucleus.
C. Mass number is the mass of the most abundant isotope.
D. Mass number is the atomic mass of a particular isotope.

Respuesta :

u can still say A but its none of the above

Explanation:

cause its the addition of protons and neutrons in a nucleus

Answer:

D. Mass number is the atomic mass of a particular isotope.

Explanation:

a-p-e-x