Final answer:
To arrange atoms according to size, compare their atomic radii. Atomic radius generally increases down a group and decreases across a period on the periodic table.
Step-by-step explanation:
The arrangement of atoms according to size can be determined by comparing their atomic radii. The atomic radius is a measure of the size of an atom. Generally, atomic radius increases as you move down a group and decreases as you move across a period on the periodic table.
So, to arrange atoms from smallest to biggest atomic radius, you would look at their positions on the periodic table. For example, in the given options Li < N < F < I < Rb would be the order based on atomic radius.
It's important to note that ionization energy and electronegativity do not directly relate to the size of the atom, so they would not help in arranging atoms according to size.