multiple - choice question the modern periodic table is arranged in order of mass number color number of…

Brief Explanations:

The modern periodic table arranges elements by atomic number, which is equal to the number of protons in an atom's nucleus. Mass number is the sum of protons and neutrons and not the basis of arrangement. Color is not a factor in the periodic - table arrangement, and the number of neutrons varies among isotopes and is not used for the overall arrangement.

Answer:

number of protons