The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?

Name: The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?
Brand: Quizplus
Rating: 4.9 (43 reviews)

Question

Quizplus · Accepted Answer

The mass number is the sum of protons and neutrons in an atom. Thus, 
mass number = number of protons + number of neutrons 
For sodium, 
mass number = 11 (protons) + 12 (neutrons) = 23 
Therefore, the correct answer is C (23).

The Sodium Atom Contains 11 Electrons, 11 Protons, and 12