Chemistry
Transition State
Quick fact
The transition state is so short-lived—lasting only about 10⁻¹⁵ seconds, the time of a single bond vibration—that it can never be isolated or observed directly; scientists infer its structure from kinetics and quantum calculations.
Why this is interesting
Imagine a ball rolling up a hill to reach the other side—it must first climb to the top. In a chemical reaction, molecules face a similar invisible hill: the transition state. What happens at that exact peak?