Oxygen has an atomic number of 8 and a mass number of 16. Thus, what is the atomic mass of an oxygen atom?

Question

Quizplus · Accepted Answer

The atomic mass of an atom is equal to the number of protons and neutrons in the nucleus. Oxygen has an atomic number of 8, meaning it has 8 protons in its nucleus. The mass number of 16 indicates that there are 8 neutrons (mass number - atomic number = number of neutrons). Adding the protons and neutrons together gives an atomic mass of approximately 16 daltons. None of the other answer choices are correct, as they do not take into account the number of neutrons in the nucleus.

Oxygen Has an Atomic Number of 8 and a Mass