Question

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Which pair of elements has maximum electronegativity difference?

AIIMS 2019

• A. $Na\text{and}F$
• B. $Li\text{and}F$
• C. $Na\text{and}Cl$
• D. $Na\text{and}Br$

Answer 1

The correct option is A $Na\text{and}F$

Among $Li$ and $Na$; $Na$ is more electropositive.
Among $F,Cl\text{and}Br$; $F$ is most electronegative.
So, $Na$ and $F$ will have the maximum electronegativity difference.

Elements	Electronegativity values (Pauling's scale)
$F$	4
$Cl$	3
$Br$	2.8
$I$	2.5
$Li$	1
$Na$	0.9

Hence, option (b) is the correct answer.