Some parts of the world have ancient lava (molten rock) flows that are hundreds of miles long. Flows such as these have come from fissures (cracks) in the crust, which have poured out runny lava. This lava is much thinner than the lava produced by explosive volcanoes, which is sometimes called pasty lava. Scientists use the term viscosity to talk about how easily a liquid flows. Thin, runny liquids have a low viscosity and thick liquids a high viscosity. The project shows the viscosities of two liquids, and how quickly they flow.
Heating solids to a sufficiently high temperature makes them melt and flow. Rock is no exception to this rule. Deep inside a volcano, hot rock becomes liquid and flows out on to the surface as lava. Its temperature can be as high as 2,2000F. Volcanoes grow in various shapes, depending on how runny or thick the lava is.
Two paper plates, pen, saucer, jar of liquid honey, tablespoon, stopwatch, pitcher of dishwashing detergent.