$\begin{array}{1 1}(a)\;\text{Activation energy for a reaction may be zero}\\(b)\;\text{The reaction having rate }=K[A][B]^{3/2}\;\text{can be an elementary reaction}\\(c)\;k=Ae^{-E/Rt},\text{E is energy above which all the colliding molecules will react}\\(d)\;k=Ae^{-E/Rt},\text{E is energy below which colliding molecules will not react.}\end{array}$
