Which process initiates when uranium isotopes achieve critical mass?

💡 Explanation

Uncontrolled nuclear chain reaction starts when the increased neutron density of isotopes reaches critical mass. This is because neutron-catalysed fission multiplies rapidly, therefore self-sustaining fission occurs, rather than alpha decay or transmutation which are slower processes.

• Which outcome initiates neutron absorption impacting tokamak fusion reactors?
• Which outcome will observers measure when subjected to extreme gravitational differentials?
• Which risk increases when strong gravitational lensing distorts distant-galaxy spacetime?
• In a closed-loop catalytic converter operating near equilibrium, which outcome results when exhaust flow exceeds the catalyst's processing capacity?
• Which consequence results when the electron wave function overlap integral approaches zero?
• Which rate-limiting outcome occurs when catalytic converters become excessively sulfurized?