Step-by-step explanation:
When three or more particles collide with each other then there are less chances that all of them collide with correct energy and orientation.
So, it is very important for the occurrence of a chemical reaction that its particles or molecules which are taking place in the reaction should have a sufficient amount of energy.
Also, these particles must collide with proper orientation so that they combine at the correct location to result in the formation of product(s).
Thus, we can conclude that energy and proper orientation determines whether a reaction will take place.