Zirconium wire was used in older style flashbulbs.
Zirconium does have radioactive isotopes, but the main ones used in industry are not radioactive.
Zirconium is not used in incandescent lamps.
Electrolysis
It is possible as zirconium alloys (zirconium metallic glasses) or zirconium dioxide ceramics.
In the nature zirconium is found as zirconium silicate or other compounds.
Zirconium does have radioactive isotopes, but the main ones used in industry are not radioactive.
The alloy zirconium-aluminium is used for some components for planes.
no
Polonium is not used in photography.
The toxicity of zirconium is not very important; only the inhalation of zirconium and zirconium compounds powders is dangerous (as for many other materials) - leading to pneumoconioses. Also zirconium can be pyrophoric at high temperatures, in powdr form. Zirconium is used for surgical implants, stomatology - as zirconium dioxide, im some cosmetics. No nutitional use.
Zirconium is used in jewelry, in the nuclear industry for cladding fuel elements since it has a low absorption cross section for neutrons, in chemical industry where corrosive agents are employed, is used as an alloying agent in steel and for making surgical appliances, it also superconducts at low temperatures and zirconium/niobium alloys are used to make superconductor magnets, and is used as a "getter" in vacuum tubes, in flash bulbs for photography, in explosive primers, and in lamp filaments. Sorry that's all I could come up with for right now, I have to get back to my research but i hope it answers your question.
Zirconium is primarily used in natural reactors, especially in the cladding of fuel rods. It is a corrosion resistant metal.
Zirconium is not used in incandescent lamps.
Yes it is.
Electrolysis
No, silve nitrate is used in photography
aluminuim is used in flashlight photography