The number with the greatest numerical value in an element's square on the periodic table represents the atomic mass , which accounts for the total of protons and neutrons. The atomic number is usually smaller and indicates the number of protons only. For example, Carbon has an atomic mass of about 12.01 and an atomic number of 6. ;
The number with the greatest numerical value in an element's square on the periodic table represents the atomic mass. The atomic mass reflects the total number of protons and neutrons, while the atomic number indicates only the number of protons. Therefore, the correct answer is D. atomic mass.
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