Light photons strike the radium atom, bumping its electrons into a higher orbit. After the sun sets and it gets dark, those electrons spontaneously drop into lower orbits, emitting a particle and ...

That is, it was roughly the same consistency throughout, with negatively-charged electrons scattered about ... emitted by the radioactive element radium) at a sheet of gold foil only 1/3000 ...

When radioactive materials emit radiation, not only does it not glow green, it does not glow at all. Ionising radiation, ...