We made a volcano... but, why did we do a simple volcano? It's easy, well... volcanos are not a simple thing, I mean, they are not just a rupture in the surface which allows hot lava and volcanic ashes.
Generally, they're formed at the boundaries of the tecntonic plates, inside has open fires where the lava rises from the magma chamber, a reservoir where lava accumulates.
So, what we did for our science fair was a little volcano which would represent a real volcano eruption so people could understand better the process it requires.
Step 1: Volcanoes!
A volcano is an opening, or rupture, in a planet's surface which allows hot, molten rock, ash, and gases to escape from below the surface. Volcanic activity involving the extrusion of rock tends to form mountains or features like mountains over a period of time.
Volcanoes are generally found where tectonic plates are diverging. Volcanoes can also form where there is stretching and thinning of the Earth's crust.