Volcanoes

Volcanic belts form along

• islands in the Pacific Ocean
• North American mountain ranges
• the boundaries of Earth's plates
• the coast of Antarctica

The formation of the Hawaiian Islands is one example of

• volcanoes forming over a hot spot
• volcanoes forming along a plate boundary
• the Ring of Fire
• continental drift

Liquid magma flows upward through cracks in rock because it is 

• highly fluid
• less dense than the surrounding solid material
• highly magnetic
• more dense than the surrounding solid material

The long tube in the ground that connects the magma chamber to Earth's surface is called the

• vent
• side vent
• pipe
• crater

Pahoehoe is 

• cooler, slower moving lava
• fast moving lava
• volcanic ash 
• lava with a rough, chunky surface

When groundwater heated by magma rises to the surface and collects in a natural pond, it is called a 

• hot spring
• geyser
• vent
• pyroclastic flows

Tall, cone-shaped mountains in which layers of lava alternate with layers of ash are called

• shield volcanoes
• cinder cone volcanoes
• composite volcanoes
• lava plateaus

Because Mercury and Mars are smaller than Earth and their cores have cooled, scientists think that

• the volcanic activtiy on these planets has just begun
• the volcanic activity on these planets has ended
• there never was volcanic activity on these planets
• the volcanoes on these planets are smaller and cooler than those on Earth

Before lava reaches the surface it is called

• rock
• magma
• volcanic ash
• liquid fire

A volcano that may erupt again at some time in the distant future is 

• active
• dormant
• explosive
• extinct