a) Activation Energy, The energy required to for an intermediate called activated complex (C ) during a chemical reaction is called activatin energy.
b) Collision frequency : The number of collisions per second per unit volume of the reaction mixture is called collision frequency (Z). For a bimolecular elementary reactions
`A+B to ` products
Rate `Z_(AB.)e^(-E_(a)//RT)`
c) Probability factor (P) with respect to Arrhenius equation : To account for effective collisions a factor p called to probability factor or steric factor is introduced.
Rate `=P Z _(AB). e^(-Ea//RT.)`