Answer:
activation energy
the minimum quantity of energy which the reacting species must possess in order to undergo a specified reaction.
effective collisions
An effective collision is defined as one in which molecules collide with sufficient energy and proper orientation, so that a reaction occurs.
ineffective collisions
An ineffective collision (A) is one that does not result in product formation. An effective collision (B) is one in which chemical bonds are broken and a product is formed.