Question

The mass number of an element is equal to ____.

Answer 1

Mass number is the total number of protons and neutrons in the nucleus

Answer 2

Answer: b. the total number of protons and neutrons in the nucleus

Explanation:

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

In an atom, when neutrons or protons are lost or gains, it directly affects the mass number of an atom.

Atomic number is defined as the number of protons or number of electrons that are present in an atom.

Atomic number = Number of electrons = Number of protons

Thus the mass number of an element is equal to the total number of protons and neutrons in the nucleus.