The "Atomic Weight" of an Atom Reflects the Average Number

Question

The "atomic weight" of an atom reflects the average number of
A) protons.
B) neutrons.
C) electrons.
D) protons + neutrons.
E) protons + neutrons + electrons.

Accepted Answer

Atomic weight is the sum of the number of protons and neutrons in an atom's nucleus, as electrons contribute very little to the mass of an atom.