1) Element: Calcium, Mass number: 40, Atomic Number: 20 # of Neutrons = # of Protons = # of Electrons = 2) Element: Chlorine, Mass number: 36, Atomic Number: 17 # of Neutrons = # of Protons = # of Electrons = 3) Element: ???, Mass number: 65, Atomic Number: 30 # of Neutrons = # of Protons = # of Electrons =