Atomic Mass = The sum of protons and neutrons in an atom. (Third option).
Atomic Number - The number of protons in an atom. (First option).
Mass Number - Exact amount of protons and neutrons (Last option).
Protons and Electrons - Charged particles of an atom (Fifth Option).
Protons and Neutrons - Particles in the Nucleus of an atom (Fourth option).
Valence Electons - Outermost particles of a shell. (Second Option).
Hope this helped!
