Question

Two elements $X$ and $Y$ combine to form a compound $XY$. Under what conditions the bond formed between them will be ionic?

• A. If the difference in electronegativities of $X$ and $Y$ is 1.7.
• B. if the difference in electronegativities of $X$ and $Y$ is more than 1.7.
• C. If the difference in electronegativities of $X$ and $Y$ is less than 1.7.
• D. If both $X$ and $Y$ are highly electronegative.

Answer 1

The correct option is B if the difference in electronegativities of $X$ and $Y$ is more than 1.7.

E.N. difference	Type of bond
0	Nonpolar covalent
0-1.6	Polar covalent
1.7	50% covalent , 50% ionic
1.7-3.3	Mainly ionic

It is the Gallis scale that explains the type of bond with E.N. difference,

so the compound $XY$ would be ionic if the E.N. difference between $X$ and $Y$ is more than 1.7.