Which of the following elements has the highest atomic mass?
Helium: 2 protons and 2 neutrons
Nitrogen: 7 protons and 7 neutrons
Oxygen: 8 protons and 8 neutrons
Hydrogen: 1 proton and no neutrons
The answer would be C since the protons and the neutrons are somewhat the same number / similar. As well as the periodic table would have somewhere in the elements "box".
