For the reaction ${\mathrm{H}}_2+{\mathrm{Br}}_2\to 2\mathrm{HBr}$, the rate expression is, rate $=\mathrm{K}\left[{\mathrm{H}}_2\right]{\left[{\mathrm{Br}}_2\right]}^{1/2}$which statement is true about this reaction

Molecularity of the reaction is 2 as one molecules of hydrogen and one molecules of bromine participates in the reaction. The order of reaction is $\frac{3}{2}$.