Which one of the following statements is incorrect?

Atomic hydrogen is produced when $\mathrm{H}_{2}$ 

molecules at a high temperature are irradiated with UV radiation.

At around $2000 \mathrm{~K}$, the dissociation of dihydrogen into its atoms is nearly $8.1 \%$.

Bond dissociation enthalpy of $\mathrm{H}_{2}$ is highest among diatomic gaseous molecules which contain a single bond.

Dihydrogen is produced on reacting zine with $\mathrm{HCl}$ as well as $\mathrm{NaOH}_{\text {(aa) }}$.