Question

why is that haloalkanes are more reactive than haloarene towards nucleophiles

Answer 1

Nucleiophile: nucleus loving, i.e attracted towards nucleus.
Since nucleiophiles are attracted towards nucleus,nucleiophile should be negetivley charged.

Haloalkanes: They are electron withdrawing groups.
Haloarens: They are electron donating groups,due to resonance.

Haloalkanes are more reactive to nucleiophile because,these are electronwithdrawing geoups and are themself positively charged,attracting the negetive nucleiophile.

Whereas haloarens have an electron cloud,surrounding the compound,making the compound negetively charged,and even the nucleiophile is negetively charged. And we know like charges repel.

Note:
#nuclieophile is negetively charged
#like charges repel,unlike charges attract