Why hydrogen bromide is electrophile?

Answer 1

hydrogen bromide is not the electrophile its bromide ion may act as the nucleophile, in alkyl halide the alkyl group may act as an electrophile.

Answer 2

Hydrogen bromide is an electrophile because the bromine atom is electronegative and attracts electron density towards itself, creating a partially positive charge on the hydrogen atom. This makes the hydrogen atom electron deficient and thus capable of accepting an electron pair from a nucleophile.