Question

$A^{+}{B}^{-}$ and $A^{-}{B}^{+}$ can be formed from elements $A$ and $B$ and we can Explain their formation based on relative values of (EN), (EA) and (IE).
$A^{+}{B}^{-}$ is formed if:

• A. electronegativity of $A<B$.
• B. electronegativity of $A>B$.
• C. electronegativity of $A=B$.
• D. anything is possible

Answer 1

The correct option is A electronegativity of $A<B$.

$A\to A^{+}+e^{-}$ if $(IE{)}_A<(IE{)}_B$
$B+e^{-}\to B^{-}$ ir $(EA{)}_A<(EA{)}_B$
Thus, $A^{+}{B}^{-}$ is formed if $(IE{)}_A+(EA{)}_A<(IE{)}_B+(EA{)}_B$
or $\frac{(IE{)}_A+(EA{)}_A}{2}<\frac{(IE{)}_B+(EA{)}_B}{2}$
or $(EN{)}_A<(EN{)}_B$
Thus, $A^{+}{B}^{-}$ exists if electronegativity of $A<B$. Similarly, $A^{-}{B}^{+}$ is formed if electronegativity of $A>B$.