Activation Energy: This is another term for energy barrier – it's the minimum amount of energy needed for a reaction to occur.
Potential Energy Diagrams: These diagrams show how much potential energy molecules have at different stages during reactions. It’s like mapping out how much effort you'll need at different points when pushing that boulder up and over the hill.
Transition State/Activated Complex: This refers to an unstable arrangement of atoms that exists momentarily at peak point in activation-energy diagram before transforming into products. It’s like the boulder teetering at the top of the hill before it starts to roll down.