The mass number for an element is composed of which of the following?

Question

Quizplus · Accepted Answer

The mass number of an element is the sum of the number of protons and neutrons in the nucleus. Therefore, the correct answer is B, which states that the mass number is composed of protons and neutrons. Electrons do not contribute to the mass number because they have a negligible mass compared to protons and neutrons. Similarly, neutrons and electrons alone cannot determine the mass number, as it requires the number of protons to be known as well.

The Mass Number for an Element Is Composed of Which