-9) Which bond has the greatest ionic character?
Explanation :
Ionic character depends on the electronegativity difference between the bonding elements. The greatest the elctronegativity diffference the greatest the ionic character.
Here in the given options, H-F has has the greatest ionic character. The electronegativity of Hydrogen is 2.1 and that of Fluorine is 4. Now the electronegativity difference is 4 - 2.1 = 1.9.