Question

the atomic mass is the number of …… in an atom. protons electons protons + neutrons neutrons

Explanation:

Atomic mass is approximately the sum of the number of protons and neutrons in an atom's nucleus (electrons have negligible mass). So the correct option is the one with "Protons + Neutrons".

Answer:

C. Protons + Neutrons (assuming the green option is labeled as C; if the original labels differ, adjust the identifier but the text is "Protons + Neutrons")