Identify the correct statement about the atomic number and mass number of an atom.

Atomic number is equivalent to the number of neutrons while the mass number is equivalent to the sum of the number of protons and number of electrons.

Atomic number is equivalent to the number of protons while the mass number is equivalent to the sum of the number of protons and number of neutrons.

Atomic number is equivalent to the sum of the number of protons and number of neutrons while the mass number is equivalent to the number of protons.

Atomic number is equivalent to the sum of the number of protons and number of electrons while the mass number is equivalent to the number of neutrons.