I do not understand what you are asking because of a definition problem. A nuclear bomb can be either a fission or fusion bomb. Also a physical crash of nuclear devices is most likely to simply detonate their conventional explosives regardless of whether they are fission or fusion (although modern low shock sensitivity explosives make this less likely than it was).
fission and/or fusion
hydrogen bomb, or a nuclear bomb
If you are asking which has the maximum danger, a hydrogen bomb is one type of nuclear bomb. In general, nuclear bombs can be fission (called atomic) or fusion (hydrogen) A fusion bomb is larger than an fission bomb, and actually uses a fission bomb to start the fusion reaction.
hydrogen bomb, or a nuclear bomb
first fission bomb 1945first fusion bomb 1954
Nuclear fusion.
nuclear fusion
Nuclear fusion.
Nuclear bomb can mean either fission or fusion bomb. Hydrogen bomb means fusion bomb. The fusion bomb can be built with any yield one wants, just by adding more stages with more fuel. The fission bomb has a theoretical maximum yield that cannot be exceeded.
fusion bomb explosion
Fusion
The nuclear fusion uses Hydrogen to produce Helium. The fusion also releases a lot of energy, which is what causes the explosion.