question_answer 38)

The increasing order of reactivity among group 1 elements is \[Li\text{ }

Answer:

The elements of group 1 have the tendency to lose the valence electron easily and this tendency increases from Li to Cs as the value of ionisation enthalpy decreases from Li to Cs and thereby chemical activity increases. The elements of group 17 have the tendency to gain one more electron to saturate the outermost shell. This tendency decreases from F to \[I\]as their electrode potentials decrease from F to \[I\] and thereby their reactivity decreases, i.e., \[F\text{ }>\text{ }Cl\text{ }>\text{ }Br\text{ }>\text{ }I\].