Question

PLEASE NEED HELP QUICK DEADLINE SOON
The atomic mass of an element can be approximated by adding the number of _______ plus the average number of _______.
A.
protons; electrons
B.
protons; isotopes
C.
neutrons; electrons
D.
protons; neutrons

Answer 1

Answer:

D. Protons ; neutrons.

Explanation:

For a given element the number of protons is fixed, but the number of neutrons differ because the element usually consist of a number of isotopes.

For example Carbon has isotopes which contain 12, 13 and 14 neutrons.

So that is why you average the number of neutrons to find the approximate atomic mass..