What is an Ionic Character?
Ionic character is a measure of the polarity of a bond. It depends upon the difference in electronegativity of two bonded atoms, more is a difference in electronegativity high will be an ionic character.
Bond between identical atoms:
When a bond is between identical atoms, the electronegativity difference is zero and the ionic character is zero. So the bond is 100% covalent.
Bond between non- identical atoms:
On the other hand bond between dissimilar atoms has some ionic character however there is no 100% ionic bond.
Relationship between electronegativity and percent ionic character: