The greatest amount of energy released is due to the fission (atomic bomb) or fusion (hydrogen bomb) reaction after the the weapon is detonated by one of several means (gun-type trigger, implosion, or boost method).
Fission reactions are responsible in most detonations for the greatest amount of energy released; this is due to the fact that hydrogen bombs (fusion) use fission explosions as a detonator, and that the fusion process can also cause further fission reactions.
blast
Blast effect
blast wave
As with any bomb the primary effect is blast.
blast effect
Blast effect.
blast
blast effects
Correct answer is blast effect
blast effect
blast wave overpressure
radiation effect