Describe how crust forming on the surface of lava illustrates the principle that removing heat from a system may result in a change in state.

Lava is defined as a molten rock that is from a volcano or from a fissure in the surface of the earth.

The lava that is very near the heat source is in a liquid state because it melted in the extreme heat. The farther away it moves from the heat source, the cooler it becomes until such time that it solidifies into rocks.