What is Neptunium Flammability?

Answer 1

While it the atmosphere of nepune does contain a lot of flamable hydrogen it contains relatively little oxygen, which is needed for hydrogen to burn. So if you were to light a match on Neptune the match would simply go out.

Answer 2

Uranium and all the transuranic elements can form critical masses. However many of these elements have too high a spontaneous fission rate to produce a reliable explosion (instead the critical mass will melt, producing an insignificant yield). Neptunium's spontaneous fission rate is low enough that it should be able to produce an explosion.

The main problem however would be producing the necessary quantity of Neptunium in reactors, as the Neptunium-239 produced from the plentiful Uranium-238 will decay within a few days to Plutonium-239. The only Neptunium isotope with a long enough halflife and a large enough fission crosssection to be suitable for a bomb is Neptunium-236, which would have to be made in a reactor from Uranium-235 (which is already a suitable nuclear explosive fuel), so why bother with the extra effort.

Answer 3

Neptunium can form a critical mass and explode; but up today Np was not used in nuclear weapons.

Answer 4

Neptunium is not a flammable material.

Answer 5

Neodymium burn after 150 0C.

Answer 6

Neptunium as a powder is pyrophoric.