The collision number (Z) is the number of collisions occurring between reactant molecules per unit time. Since molecules can only react when they collide, the reaction rate is proportional to Z. However, not every collision leads to reaction: only those with sufficient energy and the correct orientation are effective.

碰撞数(Z)是单位时间内反应物分子之间发生碰撞的次数。由于分子只有碰撞才能反应,反应速率与 Z 成正比。然而并非每次碰撞都导致反应:只有具备足够能量和正确取向的碰撞才是有效的。