Question

a bond with the most ioic character hae a electronegativity of?

Answer 1

We choose the most non-electronegative element with the most electronegative element for best difference in electronegativity to give the most ionic characteristics
Francium fluoride, FrF?
Francium is radioactive and decays in seconds, so your best answer will be
Cesium fluoride, CsF

Answer 2

a bond doesn't "have" an electronegativity; it's the DIFFERENCE in the electronegativities of the elements that make the bond that will determine whether the bond is nonpolar, polar, or ionic.

The most ionic bonds are the bonds that have the largest difference in ENEG between the 2 atoms. @.Sam. is right in the opposite corners of the periodic table result in bonds with the largest ENEG differences.