Chemistry
Unimolecular Gas-Phase Decomposition Reactions and the Lindemann Mechanism
Quick fact
The Lindemann mechanism was proposed by Frederick Lindemann in 1921 and was the first successful explanation of why unimolecular reactions show first-order kinetics at high pressures but become second-order at low pressures.
Why this is interesting
You might think a single molecule falling apart is a simple, one-step event. But in a gas, even a 'unimolecular' decomposition actually depends on collisions with other molecules—so how can it be unimolecular?