Earth’s structure & plate boundaries

1. What do we call molten rock while it is still beneath Earth’s surface, before it erupts as lava: magma or shale?

2. Which type of crust is denser and thinner, causing it to subduct beneath continental crust: oceanic crust or continental crust?

3. What class of rock forms when molten magma or lava cools and solidifies (e.g. basalt and granite): igneous or sedimentary?

4. What type of plate boundary occurs where two plates collide, forming fold mountains or subduction trenches: convergent or transform?

5. What instrument records the ground vibrations (seismic waves) produced by an earthquake: a seismometer or a barometer?

6. Which two metallic elements make up most of Earth’s dense core: iron and nickel, or sodium and potassium?

7. What generates Earth’s global magnetic field (magnetosphere): convection of liquid metal in the outer core, or ocean tides?

8. What ocean wave can be triggered when a powerful submarine earthquake vertically displaces the seafloor: a tsunami or a spring tide?

9. What is the point on Earth’s surface directly above the underground focus (hypocentre) of an earthquake called: the epicentre or the crater?

10. Why are fossils almost always found in sedimentary rock rather than igneous rock: molten magma destroys organic remains, or sedimentary rock forms in volcanoes?

11. When slow-cooling magma solidifies deep underground (such as granite), does it form large visible crystals or no crystals?

12. What class of rock forms when existing rock is transformed by high heat and pressure without melting (e.g. limestone becoming marble): metamorphic or igneous?