Science Experiments on What Lava Is Made Of

Film Canister Experiment

• This simple experiment demonstrates how temperature and pressure melt rock to make lava, and illustrates the mechanism by which lava is ejected from within the volcano. Fill a film canister with carbonated soda water and put on the cap. The soda water represents the lava and the canister represents the volcano. Shake the canister, which will produce pressure from the carbonation. As pressure builds, the "lava" will erupt, popping off the cap and spilling out.

Epsom Salt Lava

• Take three beakers and fill one with ice water, one with water at room temperature and one with warm tap water. Add Epsom salts to each, stirring until fully dissolved, and submerge a test tube in each beaker. Salt crystals will form on the test tubes over the next 24 hours. This experiment demonstrates the crystallization produced as lava cools into igneous rock. If the magma cools extrusively, or near the surface of the earth, crystallization occurs at temperatures lower than those under the surface, and produces smaller crystals. On the other hand, lava that cools inside the earth will generate much larger crystals because of the higher temperatures, a contrast demonstrated by the experiment.

Chocolate Rock Cycle

• In this experiment, a piece of chocolate represents a rock as it undergoes the transformations of the rock cycle. In its normal, solid form, the chocolate is like sedimentary rock. As temperature increases, the chocolate melts, becoming magma (molten rock). When it solidifies, students can study the change between molten lava and the igneous rock it forms when it cools.

Volcano

• You can use the classic baking-soda-and-vinegar volcano model to study the composition of lava: namely, molten rock. Chemically reacting the two substances will simulate the physical reaction of a volcanic eruption. The liquid explosion demonstrates the liquid nature of lava and gives a sense of how it might flow from the earth before cooling into igneous rock.