Electronegativity of an element refers to its tendency to attract a pair of electrons towards itself.
An ionic bond is formed by the complete transfer of electrons from one element to the other. This implies that the combining elements should exhibit a large difference in their electronegativity values.
In contrast, a covalent bond is formed by a mutual sharing of electrons between 2 atoms that do not differ much in their electronegativity values.
Given Electronegativity values are:
A = 0.75
B = 3.2
C = 3.7
a) The difference in electronegativity is the greatest between A and C i.e. 3.7 - 0.75 = 2.95. Hence, AC will form an ionic bond
b) The difference is least between B and C i.e. 3.7 -3.2 = 0.5. Hence, BC will form a covalent bond
c) In AC, C is more electronegative than A
C = anion and A = cation
