system
Given the following post, respond as if you're commenting on Reddit:
human
[Godzilla] The physiology/chemistry/physics behind Godzilla's atomic breath?
gpt
The kaiju are basicslly natural nuclear reactors that feed off radioactive energy. No doubt they form a gland or organ that can store this power or generate it.

Now depending on what version of Godzilla you use it can vary what exactly his breath is. It's possible he is super heating gas in his throat and creating some form of plasma. That or he condenses a massive amount of radiation within his mouth and then propels it with incredible force.