Elaborate on how the isotopes and their relative abundances affect the average atomic mass of an element.

Aaverage atomic mass comes from the mass of the isotope nucleus and is proportioned by the relative abundances.
Bthe different masses of isotope electrons gives the relative abundance and average atomic mass of the isotopes.
Cisotope mass both varies in neutron numbers and is weighted by its relative abundance to give the average atomic mass.
Dwhen calculating the average atomic mass of the element, the number of protons gives the relative abundance of the isotopes.

Verified Answer :

i would say c . isotope mass both varies in neutron numbers and its weighted by its relative abundance to give the average atomic mass. 

Answer:

c. isotope mass both varies in neutron numbers and is weighted by its relative abundance to give the average atomic mass.

Explanation:

Isotopes differ in the number of neutrons only so they have the same atomic number but different mass number. Mass number is the sum of the number of protons and neutrons.  

Relative weighted mass of an element  

= [(relative abundance of isotope 1 x molecular mass of isotope 1) + (relative abundance of isotope 1 x molecular mass of isotope 2)] / 100