the atomic mass is the atomic number plus the atomic masses of he and ne are 4 and 20 the atomic masses of he and ne the atomic masses of all elements the atomic mass of an element the atomic mass of carbon the atomic mass of hydrogen the atomic mass of sodium the atomic mass of an element is 27 the atomic mass unit the atomic mass of oxygen the atomic mass of gold the atomic mass of helium the atomic mass of potassium periodic table with atomic mass relative atomic mass relative atomic mass formula nitrogen atomic mass chlorine atomic mass atomic mass games atomic mass atomic mass definition atomic mass of iron atomic mass of sulfur atomic mass of copper