Determines what type of bond will form

Now there's an interesting question.

In general, electronegativity increases as one progresses down a period, while electronegativity decreases as one moves down the group. The most electronegative element is fluorine, while the least electronegative nonradioactive element is francium.

Electronegativity

Decreases

Pauling electronegativity 2.33 Sanderson electronegativity 2.29

Allred Rochow electronegativity 1.55

Mulliken-Jaffe electronegativity 2.41 (sp3 orbital)

Allen electronegativity no data