Put the pairs of atoms in order, with the pair that has the biggest electronegativity difference between the two atoms at the top of your list. fluorine and francium, phosphorus and lithium, nitrogen and sodium, chlorine and cesium, nitrogen and sulfur.

Electronegativity is the measure of the tendency of an atom to attract a bonding pair of electrons. In the periodic table, electronegativity increase across the period because the charges on the nucleus increase. The correct arrangement for the atoms given above is as follows
Flourine and Francium
Chlorine and Cesium
Nitrogen and Sodium
Phosphorus and Lithium
Nitrogen and Sulphur.

Protons have a positive charge and, collectively, give an element its atomic number.