Which factor contributes most to the size of an atom? the atom's number of protons the atom's number of neutrons the atom's number and arrangement of electrons the atom's number of protons, neutrons, and electrons all contribute equally to the atomic size. 3 points save answer?

The answer here is the atom's number and arrangement of electrons ,

The size of an atom depends on various factors , size of atom increases on going top to bottom in  a group as the number of valence shell increases and it decreases in a period as number of valence shell remains same but number of electrons in the valence shell increases that is it depends upon the atom's number and arrangement of electrons ,