Explosions may or may not represent a chemical change. A stick of TNT going off is a chemical explosion. A compressed gas cylinder with a failing weld that blows up while being filled is a mechanical explosion.
In the case of a volcano, the cause of the explosion is mechanical. We take a page from physics to answer this question. It is a buildup of pressure caused by heating of the magma (which may include gases and water) that causes the violent release of energy that we observe.
A chemical explosion is a very quickly chemical reaction.
sure why not
The main chemical in a battery + an explosion = a chemical reaction to a battery
A very fast combustion. So, a very fast reaction.
the physical comes from the chemical explosion
A chemical explosion is a very quickly chemical reaction.
A chemical explosion is a very quickly chemical reaction.
sure why not
earthquakes caused by a nuclear or chemical reaction
The main chemical in a battery + an explosion = a chemical reaction to a battery
A volcanic explosion is an eruption.
The chemical reaction causes heat, which causes the material to expand and result in an explosion.
Chemical, an explosion is essentially extremely fast combustion which is a chemical reaction.
A very fast combustion. So, a very fast reaction.
the physical comes from the chemical explosion
Gun powder and kinetic energy
You spelled volcanic explosion correctly in the question, though volcanic eruption might be preferred.