Question

Why fluorine is too explosive and has more reactivity?

Answer 1

Hloo dear....

This may be due to the repulsive force of the lone pairs of electrons, bond cleavage of fluorine is much easier that that of other halogens.
hope it helps

Answer 2

Fluorine is reactive because it only requires a single electron to complete its octet and its atomic size is also relatively small. So it is likely to form compounds with most elements.