Which of the following statements best describes a volcano?

• A. A place within the mantle where rocks melt to generate magma.

• B. It is formed underground, heated by magma, rises to the surface, and collects in a natural pond.

• C. It is an opening on the surface of the planet or moon that allows material warmer than its surroundings to escape from its interior.

• D. It is a long tube in the ground that connects the magma chamber to Earth’s surface.

Which of the following statements are true about volcanoes?
I. Volcanoes may undergo eruption.
II. Volcanoes exist on other planets.
III. Volcanoes are sources of geothermal energy.
IV. Volcanoes give information about inner Earth.

• A. I and II

• B. II and III

• C. I, II, and III

• D. I, II, III, and IV

What type of volcano forms from wide, thin layers of lava?

• C. Shield volcano

• A. Cinder cones

• B. Composite volcanoes

• D. Lava domes

What type of volcanoes are formed from particles and blobs of lava ejected from a single vent at the top, but they don’t get taller than around 1,000 feet?

• A. Cinder cones

• B. Composite volcanoes

• C. Shield volcanoes

• D. Lava domes

Mt. Kilauea in Hawaii is a type of volcano formed from loose, fluid lava that flows over each other. What type of volcano is it?

• A. Shield volcano

• B. Composite volcano

• C. Cinder cone volcano

• D. None of these

Which of these describes the difference between active and inactive volcanoes?

• A. Materials they emit

• B. The age of the volcanoes

• C. The place where they are located

• D. Historical record of eruptions or volcanic activity

A volcano in Hawaii was found to have erupted 10,000 years ago. Which best describes its type?

• A. Active, because the supply of magma from this volcano is high.

• B. Inactive, because the supply of magma from this volcano is depleted.

• C. Inactive, because it has no recorded eruption for the last 10,000 years.

• D. Active volcano, because it has had a recorded eruption for the last 10,000 years.

What are the primary factors that determine the explosiveness of a volcanic eruption?

• A. Lava temperature and volcano height

• B. Magma viscosity and gas content

• C. Proximity to tectonic plates and soil type

• D. Frequency of past eruptions

What are the characteristics of magma that create explosive eruptions?

• A. High gas content and high viscosity

• B. Low gas content and low viscosity

• C. High gas content and low viscosity

• D. Low gas content and high viscosity

The term viscosity refers to a liquid’s resistance to flow. The magma with the highest viscosity would have:

• A. High silica content and high temperature

• B. High silica content and low temperature

• C. Low silica content and high temperature

• D. Low silica content and low temperature