Question

Element $‘X^{\prime }$ : It is the most electropositive element
of the Modern Periodic Table.

Element $‘Y^{\prime }$ : It is the most electronegative element of the Modern Periodic Table.

Elements $‘X^{\prime }\text{and}‘Y^{\prime }$ respectively are

• A. $Cs\text{and}F$
• B. $Br\text{and}Li$
• C. $Br\text{and}Cs$
• D. $F\text{and}Ca$

Answer 1

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

Electropositive nature of the element decreases across a period and increases down the group.
Electronegative nature of the element decreases down the group and increases across a period.
Hence, the most electropositive element is Cesium and the most electronegative element is Fluorine.
Option b is the correct answer.