what can explode?

hydrogen gas can.

grain elevators can.
many other things can.

anything combustable, meaning it has the ability to explode.

There are various objects and substances that have the potential to explode under certain conditions. Explosions typically occur when there is a rapid release of energy. Here are a few examples:

1. Chemicals: Some chemicals, like nitroglycerin or dynamite, are intentionally designed to explode when triggered by heat, shock, or friction.

2. Gases: Highly flammable gases, such as propane or hydrogen, can explode if they come into contact with an ignition source like a spark, flame, or electric current.

3. Fireworks: Fireworks contain a mixture of chemicals that, when ignited, undergo rapid combustion, resulting in explosive effects.

4. Munitions: Ammunition, grenades, or other military explosives are designed to explode when activated mechanically or by a timed fuse.

5. Pressure vessels: Containers like boilers, gas cylinders, or even soda cans can explode if the pressure inside exceeds their structural limits, leading to a sudden release of energy.

6. Volcanic eruptions: When pressure builds up inside a volcano and magma (molten rock) rises to the surface, it can cause a violent explosion.

Determining what can explode requires an understanding of the specific conditions and circumstances involved. It's essential to handle potentially explosive materials with extreme caution and adhere to relevant safety protocols.