Question

What is the mass number of an atom equal to?

the number of protons plus the number of electrons in an atom


the number of protons plus the number of neutrons in a nucleus


the number of electrons circling the nucleus of an atom


the number of protons in a nucleus

Answer 1

Answer: the number of electrons circling the nucleus of an atom

Step-by-step explanation:

Answer 2

number of protons plus the number of electrons in an atom