What gives a firework its explosion?

Answer 1

It depends on the explosion. Chemical ones need heat, or shock (like nitroglycerine) or a small blast to "set off" a charge (like the detonator in a 500 pound bomb). As far as a mechanical one, a mechanical trigger like a pin in a balloon or too much pressure in a compressed gas cylinder and the mechanical failure of the container due to overpressure will do the trick. In a fission nuclear weapon, forcing enough fissile material together with a chemical explosive and holding it together a split second to permit the chain reaction to build sufficiently will set it off. For a fusion weapon, a fission weapon will be needed to create the heat and pressure around the fusion material to cause it to fuse and go off.

Answer 2

-hydrogen

-oxygen

-fuel

-heat

Answer 3

A nuclear explosion from a warhead can be triggered by the impact of the bomb hitting something else or by a chemical reaction happening inside the bomb.

Answer 4

black powder

Answer 5

Extreme pressure