Explain the collision theory of chemical reactions.

(N/A) The collision theory,proposed by $Max \ Trautz$ and $William \ Lewis$ in $1916-1918$,is based on the kinetic theory of gases. According to this theory:
$1$. $A$ chemical reaction occurs when reactant molecules collide with each other.
$2$. Not all collisions lead to a chemical reaction. Only those collisions are effective which possess a minimum amount of energy,known as $Activation \ Energy$ $(E_a)$.
$3$. Besides energy,the colliding molecules must have proper $Orientation$ to form products.
$4$. The rate of reaction is given by the expression: $Rate = Z_{AB} \times \rho \times e^{-E_a/RT}$,where $Z_{AB}$ is the collision frequency,$\rho$ is the steric factor (probability factor),and $e^{-E_a/RT}$ represents the fraction of molecules with energy equal to or greater than $E_a$.