Which factor determines the explosiveness of a volcanic eruption?

Highly explosive volcanoes tend to have magma with high silica, high viscosity, and higher gas content.

Which of the following illustrations best describes this statement? "Lava with less silica content has low viscosity that it can travel a great distance, forming a thin sheet."

A geologist observes a volcano with thick, slow-moving lava flows. Based on the information, which combination of factors is most likely present in the magma?

A researcher increases the temperature of a viscous magma sample in a laboratory experiment. Predict the changes in the sample's behavior.