Useful idea buried under abject science-writing is that quantum yields quantify how likely a chain reaction is. It's like r for COVID-19. One usually says "1.3

Useful idea buried under abject science-writing is that quantum yields quantify how likely a chain reaction is. It's like r for COVID-19. One usually says "1.3", not "130%" Quantum yields greater than 1 are possible for photo-induced or radiation-induced chain reactions, in which a single photon may trigger a long chain of transformations https://en.wikipedia.org/wiki/Quantum_yield#:~:text=Quantum%20yields%20greater%20than%201%20are%20possible%20for%20photo%2Dinduced%20or%20radiation%2Dinduced%20chain%20reactions%2C%20in%20which%20a%20single%20photon%20may%20trigger%20a%20long%20chain%20of%20transformations. https://en.wikipedia.org/wiki/Quantum_yield#:~:text=Quantum%... Diagram from the paper showing the initiation of a light-generated "avalanche" https://xcancel.com/YoichiSasaki1/status/2036808566011789536 https://xcancel.com/YoichiSasaki1/status/2036808566011789536