Volcanoes are openings in the earth’s ground. Volcanoes shoot out lava which is magma but above the ground.

Volcanoes explode because of magma that can not escape out of the ground when the tectonic plates are moving. The magma builds up and makes a magma chamber. It can get to a point where too much magma gathers in the chamber and it can’t hold any more. It causes the explosion.

by Daniel McMahon and Christopher Keith