Any explosion exposed or vented to the atmosphere. The bigger the explosion the bigger and more well formed the mushroom cloud.
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission or a combination of fission and fusion. When a nuclear device is exploded, a large fireball is created. Everything inside of this fireball vaporizes, including soil and water, and is carried upwards. This creates the mushroom cloud that we associate with a nuclear blast, detonation, or explosion. Radioactive material from the nuclear device mixes with the vaporized material in the mushroom cloud. As this vaporized radioactive material cools, it becomes condensed and forms particles, such as dust. The condensed radioactive material then falls back to the earth; this is what is known as fallout. Because fallout is in the form of particles, it can be carried long distances on wind currents and end up miles from the site of the explosion. Fallout is radioactive and can cause contamination of anything on which it lands, including food and water supplies. A nuclear detonation creates a severe environment including blast, thermal pulse, neutrons, x- and gamma-rays, radiation, electromagnetic pulse (EMP), and ionization of the upper atmosphere.
Cloud condensation nuclei (CCN) are usually Sulfate aerosol (SO42- and methanesulfonic acid droplets).
Alpha Particle
The energy of a firecracker is stored in the form of gunpowder , a solid . The energy is released by ignition , where it is first transformed to heat energy , then to a gas , which causes the explosion , or release of energy.
Chemical
Any: conventional, nuclear, or impact can cause a mushroom cloud.
sub surface explosion 100 KT at 25 meter below
a radioactive fallout cloud
A nuclear detination
Surface burst
Surface
Nimbus
Many nuclear detonations will create a mushroom cloud (especially near the ground due to material from the ground being sucked up into the vacuum created by the explosion, thus forming a large part of the "stem" of the cloud) and if they are near the ground, will create at least a small crater, but it sounds like you are talking about a groundburst detonation (as opposed to an airburst). These types of explosions carry more radioactive debris from the ground into the air and generate a lot of fallout due to the irradiated debris from the explosion.
A shallow subsurface burst.
The formation of a Nimbostratus cloud otherwise known as Nimbus cloud causes steady rain. This type of cloud is 2,000 meters in thickness.
Any type of nuclear explosion will have this effect.
surface burst