what is a nuclear radiation?
Radiation resulting from nuclear reactions. The most common are alpha particles (He4 nuclei), beta particles (electrons), gamma rays (very high energy electromagnetic radiation) and neutrons.
It is a process of radioactive matter emitting various matter components, electromagnetic rays and particles, thru re-composition of the matter itself. In other words the reason for nuclear radiation is that radioactive matter contains too many extra particles that can commute energy and are very unstable, "unfixed" in the matter and that's why they leave it, creating nuclear radiation.
It's not really a matter of containing "extra" particles. Beta decayers don't have an electron or positron in them, waiting to get out. Those are created, along with the antineutrino or neutrino. Similarly with photons - these are created at the time of the interaction.
Some nuclei can get to a lower energy state. Nuclear radiation is the energy they shed, in whatever form, to get to that state.
Correct. It was supposed to be also "potentially extra", they can be there or as you've just saud be created in the process, because in the end they are the radiation itself. I must also say that we rely a lot on the approximate knowledge too, standard formulas are accepted as a final and unarguable knowledge whereas it is only the most "real" theory. Because we progress, I believe there will be more re-thinking and ultimately more discoveries...
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