Which of the following pairs of elements has the greatest difference in electronegativity?

The pair of elements that has the greatest difference in electronegativity is Na and F. Electronegativity is the ability of an atom to attract electrons towards itself in a chemical bond. Fluorine (F) is the most electronegative element in the periodic table, meaning it has the strongest ability to attract electrons. Sodium (Na) is a metal and has a low electronegativity. When sodium and fluorine combine to form an ionic compound, such as NaF, fluorine gains an electron from sodium to form an anion with a negative charge, while sodium becomes a cation with a positive charge. The electronegativity difference between sodium and fluorine is the largest among the options given, making it the pair with the strongest ionic bond. Therefore, Na and F have the greatest difference in electronegativity.