What is the relationship between electronegativity and the ionic character of a chemical bond?

To predict the number of shearing electron between the two atoms (ionic bond) the concept of electronegativity is used.In the other words the ability of atoms to attracts the electron is known as electronegativity of the atom.

If the electronegativity between two atoms is greater than 1.7 then these types of bond is known as ionic bond.These types of bond will show ionic character.

4d^55s^1 ( third choice)