Since in the main topic most people are concerned about radioactive elements and not every idea got reply, i will put my idea into a new topic. I suggest two new elements:
1) Mine (i mean explosive device). When something touches it, it explodes. Obviously solid
2) White phosphorus. Glows (except low pressure), ignites other flammable elements, kills stickman. For the more functionality can be radioactive and emit neutrons.
first off, we need to keep a general consensus of realism.
White phosphorus can be very explosive and reactive on its own, if any new radio active element were to be implemented it would not be in the form of phosphorus.
Plus, I believe the community is moving toward two new radioactive pieces, something with alpha or beta particles which will interact on their own in some way, and maybe a radioactive solid or gas such as Radon or something else that is common
How would gamma radiation work? it is just Photons. Maybe they could be green photons, and they change things. Some mods have mutagenic photons, If gamma were to be implemented, than I think that MUTP should just be changed green and emitted from nuclear materials (maybe it could ionize NBLE?).
Ohh! another idea, once again it involves changing a mod element, Mutagenic Neutrons, into beta radiation. MUNE zooms around for a little while, changing things and disappearing, i think a dark blue recolor and being emitted from radioactive stuff would be a pretty cool beta particle...