Which is the best definition of activation energy

the minimum quantity of energy that the reacting species must possess in order to undergo a specified reaction.

the law of original horizontality explains:   why rocks appear in layers. correct answer: b the law suggests that all rock layers are originally laid down (deposited) horizontally and can later be deformed.   the principle is used by geologists to make assumptions about the relative ages of sedimentary rocks.

answer; nociceptive pain;